This paper studies the spatial distribution laws of rotor deformation of interior permanent magnet synchronous motors (IPMSMs) with V-shaped rotor structures. The structural-electromagnetic finite element models of IPMSMs with deformed and undeformed rotors are developed to investigate the effect of different rotor deformation types on the magnetic radial forces at no-load and on-load conditions. The change laws between rotor deformation and radial force density are obtained and the result is helpful in solving problems of mutual influence between electromagnetic and mechanical characteristics during the engineering design of in-wheel motor.