Large current solid-insulation-embedded poles must use soft connection. It causes partial discharge andsurface discharge. So it is of great significance for the analysis and optimization design of insulation structure. Theelectric field distribution of 40.5 kV embedded pole is obtained by using the finite element analysis method

and theelectric field concentration area’s distribution of the gas domain nearby bolts and soft connection is extracted. It is ob-vious that the electric field distortion of SF6 near soft connection

resulting in larger partial discharge and surface dis-charge. According to composite insulation electric field theory

an optimization method is proposed to cast shieldingnet around the soft connection in solid-insulation-embedded pole

and made shielding net and soft connection equi-potential. Through electric analysis

the maximum field strength of the SF6 gas near bolt decreased from 12 kV/mm to7.5 k V/mm

which confirmed the theoretical feasibility of the optimization design. Partial discharge tests show thatthe optimized embedded pole’s magnitude of partial discharge decreased from 203.98 pC to 2.37 pC. Peak withstandvoltage of lightning impulse test increased from162 kV to 215 kV

It confirmed the feasibility of the optimization mea-sures in engineering applications

which provided reference for optimization design of large-current solid-insulation-embedded pole and high voltage apparatus composite insulation electric field.