but ,if i use busy as flollowing way,is it right? he is busy to do his work No, you need to say. He is too busy to do his work. (means he has too many other things to take care of, so he can't do his work)

Dave is right, He is too busy to do sth = He is too busy that he can not do sth. for example: "I'm too busy to answer your question" means "I'm busy doing my job so that I can't answer you question."

He is too busy to do it - For example he is too busy to come to the concert (as he has some work to do). Same situation can be explained as *He is too busy doing his work (so he can't come to the comcert). So those are the ways you can use *busy*. Any of them is right, just depends how you want to say it.

This is an excellent online dictionary which will help you with your question and others you might have in future: www.thefreedictionary.com

there are different ways to use the word " busy " in sentences , and the meaning differs too . 1- busy (with sth/sb) :having a lot to do; perhaps not free to do sth else because you are working on sth: Are you busy tonight? Kate’s busy with her homework. 2- busy (doing sth) spending a lot of time on sth: James is busy practising for the school concert. Let’s get busy with the clearing up .PLACE 3- full of people, activity, vehicles, etc.: a busy main road Victoria is one of London’s busiest stations. PERIOD OF TIME 4- full of work and activity: Have you had a busy day? This is one of the busiest times of the year for the department. TELEPHONE 5- (especially NAmE) being used SYN engaged: The line is busy—I’ll try again later. the busy signal PATTERN / DESIGN 6-too full of small details He was busily engaged repairing his bike.