The invention relates to a pneumatic zero-speed hole-pricking liquid fertilizer deep application mechanism and belongs to agricultural machinery. N liquid fertilizer application needle assemblies are inserted in a moving flat plate in a telescopic movable mode; a pressing plate is assembled on the upper parts of the liquid fertilizer application needle assemblies; a steel pipe and a support are fixedly arranged on the moving flat plate; the steel pipe is communicated with the liquid fertilizer application needle assemblies; an air cylinder rod arranged on a vertical air cylinder on the support is connected with the pressing plate; the moving flat plate is arranged on the back side part of a fixedly arranged horizontal air cylinder; a main gas pipe is used for communicating a gas pump with an air cylinder motion controller; a lead is used for communicating a speed measuring sensor with the air cylinder motion controller; the horizontal air cylinder is used for communicating the air cylinder motion controller with the horizontal air cylinder; a gas pipe of the vertical air cylinder is used for communicating the air cylinder motion controller with the vertical air cylinder; and a hose is used for communicating a liquid pump with the steel pipe. The pneumatic zero-speed hole-pricking liquid fertilizer deep application mechanism is reasonable in structure, high in automation degree, high in hole-pricking operation and fertilizer application operation quality, high in fertilizer efficiency utilization rate and low in environmental pollution, and is favorable for growth and absorption of crops.