In order to solve the problems of heterogeneity，high temperature and high salt in the oilfield exploitation，the technical idea of preparing particle oil displacement agents with small molecule crosslinking agents was broken through，and a series of particles type oil-displacing agents were synthesized with a variety of new macromolecular crosslinkers，and the network structure， mechanical properties， aging resistance and migration mechanism was studied. The research results showed that the macromolecular crosslinking agent could effectively improve the uniformity of the gel and endow the gel with excellent mechanical properties. The breaking elongation of the three gels prepared with macromolecular crosslinking agent was above 2000%，the breaking strength was above 0.3 MPa，and could be compressed to 90% without being damaged. Among them，MCH0.5-30 had the best performance，the breaking elongation could reach up to 2800%，and the breaking strength could reach up to 0.6 MPa. In addition，it had a high modulus retention rate after aging in brine with a salinity of 30 g/L at 85℃ for 90 days，showing excellent aging resistance. Macromolecular crosslinking agents provide new ideas for the preparation of high-performance oil-displacing agent，which are expected to be applied in harsh oil reservoirs with high temperature and high salinity.