Disclosed is a helical turbine power generation system for generating electricity by using a helical turbine and a synchronous generator, the system including: a helical turbine rotatably provided in a frame so as to continuously generate rotation force under unidirectional or multidirectional fluid flow; a step-up gear for increasing a rotational velocity of the helical turbine up to a level required for generating electricity; a fluid coupling for preventing the rotational velocity increased by the step-up gear from increasing above a required velocity at a temporarily high rate of fluid flow; and a synchronous generator for generating electricity by using the rotational velocity transferred from the fluid coupling. Therefore, it is possible to reduce equipment costs and to prevent environmental pollution.