Electrical grade silicon powder is a kind of active silicon powder, which is used as epoxy resin insulation sealing filler for electrical products. It can not only greatly increase the filling amount, but also reduce the viscosity of the mixture system, improve the processing performance, improve the permeability of the mixture to the coils of high-voltage electrical appliances, and reduce the expansion coefficient of the cured product and the shrinkage during curing, It plays a beneficial role in feeding the thermal tension difference between the mixture and the coil and improving the thermal, electrical and mechanical properties of the cured product.