Thanks for pointing out this, being consice is always my weakest point.

Clear and simple at 311 words. Some sentences could be shorter: your average sentence length is 18 words, and you should try to reduce this to between 12 and 15 words. Add some short sentences or break up long ones.

Word Choice/Usage

• how to avoid detriment → how to avoid injury OR how to reduce risk
• People want to overcome fear against certain things → People want to overcome their fear of certain things
• such as giving speech in front of crowd → such as giving speeches OR such as giving a speech in front of a crowd
• people like to play dangerous sports for conquer fears → people like to play dangerous sports to conquer fears
• they have to take suitable actions → they have to take suitable action
• far and away the most important thing to do is… → By far and away the most important thing to do is…

Avoid vague words/Shorten/Combine

• It is often a good way to relieve anxiety and tension which come from various aspects.
  It is a good way to relieve anxiety and tension from our everyday life
  OR It is a good way to relieve everyday anxiety and tension.
• by completing adventurous missions in the sports → by completing adventurous sports challenges
• participants are in good health conditions → participants are healthy
• More importantly, insurance is of great necessity, as this is the safety net for saving their lives as well as compensating their families. →
  Insurance is important to cover medical costs.
• This is because the risk of being injured is very high. Sometimes, even people’s lives will be in peril.  →
  The risk of being injured or killed is very high.

Clarify

• If those risk takers are strong enough, then it is highly likely that they will survive after some horrific and tragic accidents. →
  If participants are strong, healthy, and trained, they have more chance of avoiding serious injuries. (Nobody could survive a tragic accident!)

Overall the essay is clear and has no irrelevant detail. You could easily reduce it to about 270 words by eliminating unnecessary phrases and words, and it would flow a little better. Well done. 

Extreme sports have become commonplace in many parks and tourist attractions. Although those sports are very hazardous, they are still drawing a large number of participants. This essay will list the reasons compelling them to take part in extreme activities and give some advice about how to avoid detriment.

Most people are keen to play extreme sports for two major reasons. Perhaps the fundamental reason is that people want to overcome fear against certain things, such as giving speech in front of crowd, and gain confidence by completing adventurous missions in the sports. For example, bungee jumping, a sport which people leap off from several hundred metres high with just a rope tied with their feet, requires a great deal of courage. Many people would think that if they can finish this intimidating and life-threatening task, there is no reason they cannot deliver a speech in a big conference. Another important reason is that those sports tend to be highly stimulating. It is often a good way to relieve anxiety and tension which come from various aspects.

In terms of protection, in my opinion, far and away the most important thing to do is to ensure participants are in good health conditions. This is because the risk of being injured is very high. Sometimes, even people’s lives will be in peril. If those risk takers are strong enough, then it is highly likely that they will survive after some horrific and tragic accidents. More importantly, insurance is of great necessity, as this is the safety net for saving their lives as well as compensating their families.

In conclusion, people like to play dangerous sports for conquer fears and relaxing. However, they need to be fully aware of the consequences and risks of doing this. Meanwhile, they have to take suitable actions to protect themselves as well as their loved ones.