The invention provides a semi-underground water pumping energy storage power station based on an open pit. The semi-underground water pumping energy storage power station based on the open pit comprises a high-position water storage area, a low-position water storage area, a water conveying channel and a two-way generator set. The water conveying channel is communicated between the high-position water storage area and the low-position water storage area. The two-way generator set is arranged between the high-position water storage area and the low-position water storage area, and the two-way generator set is used for conducting water pumping energy storage or power generation through the water conveying channel. The high-position water storage area is the open pit of an abandoned mine, thelow-position water storage area is an underground water storage area, and the underground water storage area is located in an underground space of the abandoned mine. The semi-underground water pumping energy storage power station based on the open pit makes full use of an overground space and the underground space of the abandoned mine, multiple layers of underground water storage areas with different height differences are designed, the semi-underground step height difference is formed for converting potential energy and electric energy, and the water pumping energy storage reliability andstability are improved.