The relative motion of electromagnetic satellites is activated by electromagnetic force between satellites. The control law should satisfy two conditions, low calculation burden and ability of avoiding collision. The control objects are relative motion vectors of satellites to reference satellite. The analysis of feasibility of electromagnetic force control to satellite formation shows that relative motion of satellites can be controlled if electromagnetic strengths of satellites can be controlled. An artificial potential function was designed. Relative positions and relative velocities are treated as variables. The value of the function is minimal when control object is got, and it is local maximal when collision happens. By regulating control parameters in real time, which the current of electromagnetic coils won-t beyond upper limit is regarded. The derivative of artificial potential function is less than zeros in control process. Simulation shows that electromagnetic satellites configuration would be generated when control law was imposed with interference.