The invention discloses a method of acquiring a three-dimensional foot shape by using a foot shape video and sensor data acquired by a smart phone. The smart phone provided with an IMU sensor is coiled on a naked foot to shoot the foot shape video and corresponding IMU data at 360degrees, and by establishing a factor diagram, a video camera attitude, a three-dimensional point cloud coordinate, the IMU data, a video contour, and other various acquired data are used as factors, and then by defining constraint error equations among the factors and solving the equations, the parameters of the video camera are acquired, and are introduced in a reference model for foot shape reconstruction. The point cloud distribution, the normal vector, the surface curvature, and other information of the reference model are fully used to guide deformation of a reconstructed foot shape, and then under the condition of the reconstructed foot shape being not deviated from a reconstruction point cloud, the reconstructed foot shape is close to a real foot shape as much as possible, and interferences of noise points are reduced, and therefore a process of acquiring a corresponding foot shape three-dimensional grid model conveniently is realized. Acquisition costs of foot shape data are reduced, and accuracy and robustness of parameter calculation are improved.