The embodiment of the invention provides a fountain type water treatment device including a fountain main machine, a floating body, a guide cylinder and a microbial inoculum cylinder; the floating body has an annular structure; the guide cylinder is fixed at a center position of the annular structure of the floating body through a bracket and includes a water inlet and a water outlet, and the water inlet is located below the water outlet; the fountain main machine comprises a motor and an impeller, the impeller is located just below the water inlet of the guide cylinder; the motor is placed below the floating body through a connection bracket; the motor drives the impeller to rotate, so that water enters the guide cylinder from the water inlet of the guide cylinder and sprays out from the water outlet of the guide cylinder; the microbial inoculum cylinder is fixedly arranged below the floating body and is internally provided with a microbial inoculum, and the cylinder wall of the microbial inoculum cylinder is provided with meshes running through the cylinder wall. The fountain type water treatment device provided by the embodiment of the invention can solve the problem of manpower and material power consumption caused by artificial repeated dosing of the microbial inoculum.