The utility model relates to the technical field of pressure release manifolds of foam drilling, in particular to an improved pressure release manifold device of foam drilling. The improved pressure release manifold device comprises a gas-liquid conveying pipe, a one-way conveying valve, a main opening-closing valve, a stand pipe pressure release pipe, a stand pipe pressure release one-way valve, a manifold pressure release pipe, a manifold pressure release one-way valve, a stand pipe valve, a manifold valve and a sand discharge pipeline. A conveying inlet is formed in the right end of the gas-liquid conveying pipe; a conveying outlet is formed in the left end of the gas-liquid conveying pipe. The main opening-closing valve and the one-way conveying valve are sequentially and fixedly installed from the conveying inlet to the conveying outlet on the gas-liquid conveying pipe. The improved pressure release manifold device is reasonable and compact in structure and convenient to use; the manifold pressure release pipe and the stand pipe pressure release pipe are communicated with the sand discharge pipeline, pressure in a stand pipe, a drill column in a pit and a pipeline on the ground can be released into the sand discharge pipeline, noise is lowered, and safety of pressure release is improved; meanwhile, operation is convenient and the pressure release efficiency is high.