The invention discloses a control system of a telescopic boom bolt mechanism, which comprises an oil tank, a hydraulic pump, a motor and a second directional control valve which are arranged on a telescopic boom, wherein the oil tank is used for storing hydraulic oil; the hydraulic pump is used for outputting the hydraulic oil in the oil tank into a hydraulic circuit; the motor is used for driving the hydraulic pump; and the second directional control valve is used for controlling the route between the hydraulic circuit and the hydraulic pump or the oil tank to be turned on. Preferably, the control system also comprises a third one-way valve, an energy accumulator and a pressure relay; when a pressure value detected by the pressure relay is more than a preset maximum pressure value, the pressure relay outputs control signals to the motor, and the motor is switched off; and when a pressure value detected by the pressure relay is less than the maximum pressure value, the pressure relay outputs control signals to the motor, and motor is switched on. The system has simple and reasonable design, and can effectively avoid the problem that hydraulic volume in a large chamber influences the control response speed, so as to ensure the sensitive and reliable motions of an arm pin hydro cylinder and a cylinder pin hydro cylinder.