The invention belongs to the technical field of application of hydraulic servo systems, particularly relates to a protection module device for the hydraulic servo system, aims to improve the reliability and safety of the hydraulic servo system and provides the protection module device for the hydraulic servo system, which can timely effectively adopt safety protection measures of maintaining, unloading or the like for the system according to working conditions and guarantee the safety of the system and operators. The protection module device for the hydraulic servo system is characterized by comprising a valve block body (1), a servo valve (3), logic valves and electromagnetic directional valves. The protection module device for the hydraulic servo system is simple in structure, convenient to use, strong in universality and interchangeability, low in fault rate and stable in performance. The device is smaller in size, can be conveniently moved to a proper position according to needs, can be mounted by being separated from a servo hydraulic cylinder and can also be directly arranged on the servo hydraulic cylinder, and the device does not need complex operation and is simple to set.