how to distinguish between "dissatisfied" and "unsatisfied"

I view it a little differently. If I am dissatisfied it is because I don't like something, in other words, it is unsatisfactory. However, if I am unsatisfied, it's because I haven't had enough of something, I haven't had sufficient. 'Although he had eaten a lot, his hunger was still unsatisfied.'

一般不满意都用dissatisfied ,而不用unsatisfied.

不高兴用dissatisfied
未满足用unsatisfied

一般不用unsatisfied

dissatisfied是不满
你想表达没有不满，也不满意，可以用not satisfied 或者not dissatisfied

Herzberg的Two-factor Theory里面讲解了dissatisfied和not satisfied的状态

discodica's answer is correct