In order to study and improve the processability of polyolefin resin substrates, a polyolefin based substrate product was discussed, and its production process was introduced. The focus was on analyzing the moisture heat resistance, mechanical strength, and electrical properties of the board, analyzing the influencing factors and improvement measures of each performance. The results show that by introducing inorganic fillers (mass ratio 40%~70%) and using 1.5% silane coupling agent to treat the filler interface, the thermal decomposition temperature (weight loss 5%) is at 414.2 ℃, and the water absorption rate can be reduced to 0.06%, which can improve the moisture heat resistance of the board. Choose an average particle size of 5 μm SiO₂ filler, the bending strength is 310 MPa, the peel strength is 0.8 N/mm, and the drilling holes with different apertures have good pore shapes.. The content of initiator in the resin system is controlled at around 2.0%, which can ensure that the board has good electrical properties and low CTE for a long time. By optimizing the formula or regulating the process, the indicators of the board can meet the requirements of printed circuit board (PCB) processing and better meet market requirements.