The invention provides a shallowly-submerged floating type horizontal axis current power generation system with a flow guide cover or flow guide covers and belongs to the ocean current energy development technical field. The shallowly-submerged floating type horizontal axis current power generation system is of an array structure which is formed by one or more than one current power generation device; every current power generation device comprises a power generation mechanism and a floating body mechanism, wherein the power generation mechanism is arranged inside a flow direction adaptive flow guide mechanism and the floating body mechanism is connected with the flow direction adaptive flow guide mechanism; every floating body mechanism comprises a floating ball and a wing-shaped floating body which are arranged at the top of the bottom of the corresponding flow direction adaptive flow guide mechanism respectively; every flow direction adaptive flow guide mechanism comprises the glow guide cover, turbine blades and a streamlined cabin, wherein the flow guide cover faces the direction of the ocean current and the turbine blades and the streamlined cabin are arranged in the flow guide cover in turn. According to the shallowly-submerged floating type horizontal axis current power generation system with the flow guide cover or covers, the power generation can be driven by the kinetic energy of the ocean current, the shallowly-submerged floating type horizontal axis current power generation system is suitable for the stable ocean current and sea condition, the energy conversion rate is high, and one to three megawatts every hour of power can be generated after the shallowly-submerged floating type horizontal axis current power generation system is placed in the two to three meters every second of flow rate of ocean and the appropriate blade diameter is designed.