In the system of the PV grid-connected generation, because of the dispersion of the PV panel, difference of the sun radiation condition and the shadow of a part of the PV panel, they will cause the serious loss of energy for the parallel PV panel. In order to overcoming energy loss and raise the efficiency of the PV system, a new maximum power point tracking method called distributed variable step duty ratio perturb method is put forward. The distributed MPPT method overcomes the shortcomings to generate electricity quantity to descend because of the dispersion of the PV panel. The variable step duty ratio perturbing method speed quickly and is more suitable for this kind of distributed generation system. The hardware adopts DC/DC electric circuit to regulate PWM duty ratio. The software adopts TMS320-2812. An example is given to show that this method is able to realize distributed MPPT. In addition, the calculation speed of the approach is quick, accuracy of the approach is better, and the system has a high stability.