The invention discloses a floating cabin type submersible electric pump for water, which comprises a pump body and a floating cabin, wherein the floating cabin comprises a floating cabin upper cover, a floating cabin lower cover, an outer cabin wall and a water outlet pipe. The outer cabin wall is positioned on the outside of the water outlet pipe, the floating cabin upper cover is positioned above the outer cabin wall, the floating cabin lower cover is positioned below the outer cabin wall, first through holes are arranged on the periphery of the floating cabin upper cover, an upper flange plate is arranged at the top end of the water outlet pipe, a lower flange plate is arranged at the bottom end of the water outlet pipe, and the pump body is vertically placed and positioned in the water outlet pipe. The submersible electric pump can normally work in various types of water. Besides, the invention further provides an installation method for the floating cabin type submersible electric pump. The installation method includes the steps: firstly, installing steel cables; secondly, laying down the submersible electric pump to slip into the water along a bank slope; thirdly, respectively fixing the first steel cable and the second steel cable on the bank slope; and finally, fixing the third steel cable. The installation method is simple and rapid, and can be used for stably installing the submersible electric pump in the water.