This paper aims to study the application of UAV oblique photography in earthwork calculation. Taking the earthwork calculation in the excavation stage at Lishui Xiushan Park as the research object, the paper systematically elaborates the practice of UAV oblique photography technology in earthwork calculation and the key internal and external processes. The oblique photography mapping technology combined with the square grid earthwork calculation method efficiently completed the earthwork calculation, which provides an accurate reference for the relevant work inspection, and meanwhile proposes new ideas and solutions for the earthwork calculation to other similar projects, which has significance of innovation.