The invention relates to a particle image velocity measurement experimental device and method for a constant-pressure pulse jet impacting rotating wall surface. The device comprises a frequency conversion motor, a coupling, a first shaft, a second shaft, a disc, a water tank with square outside and circular inside, a CCD camera, a sheet light source, a laser, a synchronizer, a computer, a copper pipe, a pulse generator, a valve, a flowmeter, a constant water tank, a downpipe, a water pump and a water reservoir, wherein theconstant water tank is arranged on the upper side of the water reservoir, and the water tank with square outside and circular inside is arranged on the side of the water reservoir;the water tank with square outside and circular inside comprises anouter square water tank and aninner circular water tank, the inner circular water tank is arranged in the outer square water tank, the two ends of the inner circular water tank are open, one end of the inner circular water tank is fixed with the outer square water tank, and a gap is formed between the other end and the outer square water tank. The influence laws of different Reynolds numbers, impact distances, wall surface rotating speeds and pulse periods on various flow characteristics in the flow field can be researched by adopting PIVaccurately, comprehensively and systematically.