Disclosed is a helical turbine power generation system for generating electricity by using a helical turbine and an overload prevention 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; and an overload prevention generator for generating electricity by using the rotational velocity transferred from the step-up gear, and for preventing overload caused by a sudden increase in a rotational velocity. Therefore, it is possible to reduce equipment costs and to prevent environmental pollution.