Three density domestic PMI foam core were choosen as the research object to conduct pressure test of foam core, the effects of foam core density, foam core thickness and curing pressure on the curing shrinkage of PMI foam cores were explored. The effect of foam core density, glue-connected glue film layer, and molding process on the adhesive performance of PMI foam sandwich sample was researched through mechanical performance test. The test results show that the larger the foam core density and thickness, the smaller the curing pressure, the smaller the curing shrinkage, and the regression equation between the curing shrinkage and the foam core density, thickness and curing pressure was established. The mechanical performance test shows that the foam core density increases, which can significantly improve the adhesive strength between the panel and the core material. The adhesive strength of foam sandwich with 75 kg/m³ and 110 kg/m³are maximum increased by about 166% and 260% than that of the foam sandwich with 52 kg/m³, respectively. When the number of glue membrane layers increases from a single layer to two layers, the adhesive strength of foam sandwich sample is only up to about 40%, and the contribution to adhesive strength is not obvious.