The invention discloses a ship multi-beam acoustic equipment mounting process which is characterized by comprising the following steps of: dividing a guide cover into three parts, milling a mounting surface and a lower surface of the guide cover; assembling the three parts of the guide cover in an inner field, positioning a multi-beam bracket and a closing plate on the guide cover, arranging a drilling thread on the guide cover, then disassembling the multi-beam bracket and the closing plate from the guide cover, manufacturing a positioning code plate of a transmitting array; pushing the guide cover into the downside of the ship by using a roller guide rail, lifting the guide cover by using a crane for leveling, fixing the transmitting array of the guide cover by using the code plate, controlling the welding deformation of the mounting surface by using a welding code plate, welding the guide cover on the ship by adopting a symmetrical interrupted welding mode; pushing the multi-beam bracket to the downside of the guide cover by using the roller guide rail, jacking the multi-beam bracket into the guide cover by using a hydraulic trolley, adjusting the multi-beam bracket, and locking and fixing by using bolts; conveying a multi-beam module to the downside of the guide cover, mounting the multi-beam module in the multi-beam bracket by using bolts through the hydraulic trolley; and mounting the closing plate and fixing by using bolts.