A structural improvement of submersible cooling pumps, especially a submersible cooling pump that is capable of enhancing the stability and extending service life, comprising a motor set, an impeller set and a stud set, characterized in that in said motor set, there are provided on the motor casing a top plate, disposed on which is a fan with orifices, and a motor cover having sight holes and cross-shaped ventilating holes that spreads all over the cover, disposed on top of said fan, and a protection cover with a small elastic plate provided to cloak said motor cover which is screw fastened to said motor casing; the lower end of said motor casing fits on the upper rim of the trough of a fixing base, and is fastened onto the fixing hole base of said fixing base; on said fixing base an outlet port and shaft hole are provided, and by both sides of said shaft hole an ingress of water and a positioning hole that permits the screw fastening of another element are provided; said impeller set combines and fastening an upper cover and a lower cover to accommodate a set of vanes, wherein an outlet hole is provided by one side, and a fixing hole by the other side, of an inlet hole of said upper cover; and said stud set consists of a duct pipe and a support pipe, both of equal length, of which the support pipe has female thread at each end allowing it to be screw fastened to the positioning hole of said motor set and the fixing hole of said impeller set, respectively.