Abstract: In order to improve the roof control effect of the roof of the working face of the broken roof, the roof pressure characteristics and the reasonable support resistance of the supports were studied by using field measurement and theoretical calculation. The results showed that the roof motion was divided into three stages in the process of working face closing to the channel, which was relatively stable stage, the mutation movement stage and the movement stage, and the support working r esistance mutation was about 3 ~ 5 m, and the measures should be taken to protect the working resistance mutation. Existing chock support working resistance was |o W, lack of working resistance of support lead to coal wall pressure increased caused by roof subsidence quantity and coal wall for more intense, through theoretical calc ulation of pile support reasonable working resistance of support should be not less than 14 398 k N.