Electric vehicle inwheel motor often operated in complex operating conditions and harsh environments, resulting in constant changes of the current and internal electromagnetic losses of inwheel motor. The serious impact on the motor temperature rise analysis and reliable operation had happened. Taking a 4 kW inwheel motor as an example, using Maxwell electromagnetic finite element analysis software, the electromagnetic finite element model of the inwheel motor was established, and the electromagnetic field was calculated. By choosing eight common working conditions of acceleration and overload, the distribution of electromagnetic losses and the law of numerical variation of each component of inwheel motor were analyzed. From the analysis results, it could be seen that the stator iron loss increased with the increase of rotational speed, but did not change with the increase of overload multiple. The core loss of rotor could be neglected. The eddy current loss of permanent magnet increased with the increase of acceleration and overload at the same time, but the effect of acceleration condition on it was stronger. The copper loss of windings was mainly affected by the change of overload multiple, which accounted for the largest proportion of total loss and was the main heat source. An important reference for the analysis of temperature field and the design of cooling structure of inwheel motor was provided.