The invention relates to an embedded permanent brushless DC motor non-position sensor control system, composed of a microprocessor controller, a IPM module and a drive unit, a current detection circuit, a phase voltage detection circuit, an output display circuit, a control input circuit, an embedded rotor structured permanent brushless DC motor, a drive and control power source, etc. The invention judges the position of rotor by detecting variation of inductance of stator winding indirectly according to the character that the inductance of rotor winding of the embedded rotor structured permanent brushless DC motor is the function of rotor position theta. In the embedded rotor structured permanent brushless DC motor with star-shaped connection adopted by stator winding, when self inductance of two phase windings therein are equal, the position is the counter potential zero-crossing point without phase connection. Therefore, adopting non-connection phase voltage to ground continuously in one PWM period, and comparing the difference value, to judge non-connection phase counter potential zero-crossing point, and lagging behind for 30 degrees electric angel as phase-exchange time of next time. The method of the invention is indirect induction method. The non-position sensor control method of indirection induction method is nothing to do with rotating speed of motor, so that the invention overcomes the problem of malfunction at low speed of the conventional non-position sensor control method-the detection method of counter potential zero-crossing point. The invention can work reliably at ultra-low speed even if the rotating speed of motor is close to zero.