The invention discloses a multi-dimensional one-stop investigation method for a spawning fish spawning site on grasses in large water areas of rivers, lakes and reservoirs, and relates to a grass spawning fish spawning site investigation method. Aiming at the problems of fish spawning sites in fishery resource investigation and evaluation and fishery ecological environment protection, the invention aims to solve the problems of non-synchronous and non-timely investigation time, incomplete investigation content and no multi-dimensional investigation method in the existing investigation of spawning fish spawning sites on grasses in large water areas of rivers, lakes and reservoirs. The investigation method is implemented to form a one-stop investigation method of point-line-surface movement,multi-dimensional, omnibearing, long-distance, large-range and carpet-type search on the water surface, underwater and air, the timeliness is high, the efficiency is high, the amount of obtained datainformation is large, scientificity, systematicness and accuracy are high, and the ideal effect of synchronously, rapidly and systematically investigating and observing an investigation water area isachieved. The multi-dimensional one-stop investigation method is applied to the fishery field.