The invention discloses a brake-type liquid viscosity transmission device which comprises a box body, a speed governing mechanism and a brake mechanism, wherein the speed governing mechanism comprises a first shaft, a second shaft, a second shaft transparent cover, a driving friction plate, a driven friction plate, a driven drum, a driven plate, a first piston cylinder and a first control oil pipe; the brake mechanism comprises a brake shaft, a brake shaft transparent cover, a moving friction plate, a static friction plate, a brake drum, a brake plate and a second piston cylinder. According to the brake-type liquid viscosity transmission device, the idea is ingenious, the stepless speed governing function of a liquid viscosity speed governing clutch and the braking and speed reduction functions of a liquid viscosity brake are realized on the same set of device; a same set of oil pressure control system is adopted, the working conditions of the speed governing mechanism and those of the brake mechanism are mutually corresponding and collaborated, so that not only can the torque be transmitted to the transmission system as required and can the output rotating speed be adjusted steplessly, but also adjustable moment of resistance can be applied, the system is in a half-braked state for a long time, and the mutual coordination and controllability of the speed governing and the braking of the transmission system are realized.