The invention relates to a telescopic boom type dust suppression device for a fixed crushing station. The telescopic boom type dust suppression device is characterized by comprising an arm lever telescoping mechanism and a shed frame ceiling structure which are erected above a receptacle trough of the crushing station; the arm lever telescoping mechanism is composed of a fixed arm, a stretched arm set, a hydraulic station and a hydraulic driving mechanism; the shed frame ceiling structure is composed of a shed frame and dustproof and waterproof cloth covers laid on the shed frame; the shed frame is composed of transverse supporting rods and triangular supporting frames, wherein the transverse supporting rods are fixed to the two sides of the front end of the fixed arm and the two sides of the front ends of stretched arms, and the triangular supporting frames are hinged to the cantilever ends of the transverse supporting rods; winches are arranged below the fixed arm, and each triangular supporting frame is connected with the winch on the corresponding side through a steel wire rope and a turning pulley. The telescopic boom type dust suppression device is reasonable in structural design and reliable in use; the problems that an existing pure water-spraying dust suppression mode is poor in dust suppression effect, wastes water sources, is influenced by seasons and the like and can not easily meet the environmental protection requirements are solved fundamentally; the dust suppression effect is improved remarkably; hoisting, maintenance and other operation on all components of the crushing station through a bridge crane above the receptacle trough of the fixed crushing station are not affected.