A helical turbine power generation system is configured to generate electricity by using a helical turbine and an overload prevention generator. More specifically, the helical turbine is rotatably provided in a frame so as to continuously generate a rotation force under unidirectional or multidirectional fluid flow and a step-up gear is configured to increase the rotational velocity of the helical turbine up to a level required for generating electricity. Additionally, an overload prevention generator is incorporated to generate electricity by using the rotational velocity transferred from the step-up gear thereby preventing an overload caused by a sudden increase in the rotational velocity of the turbine.