The utility model discloses a bicycle brake safety governor, act as go -between on, act as go -between down and act as go -between on, including last fixed lid, main body cover, down fixed lid, cushioning fender to attach the A of knot and act as go -between on, and attach the B of knot and brake the line connection board, it is connected with two variable speed wire loops knots to go up fixed covering, fixed covering is connected with two variable speed wire loops knots down, the one end of acting as go -between on two is installed respectively to act as go -between to attach and is detained A and act as go -between on and attach knot B, the inside sliding tray that is provided with of main body cover, brake line connection board can slide from top to bottom in the sliding tray, on act as go -between to attach and detain A and act as go -between to attach on and be connected with brake line connection board again after the B of knot connects through the embedding connected mode, be provided with front brake buffering rubber ring and front brake buffer spacer between cushioning fender and the lower fixed lid. This bicycle brake safety governor simple structure, reasonable in design, the fault rate is low, can effectively avoid overturning and wag the tail the phenomenon, has improved the security of bicycle brake greatly, has improved the wholeness ability of bicycle moreover.