Oil displacement tests in etched glass micromodel，sandpacked glass model and heterogeneous parallel sandpack model were carried out to study the recovery efficiency of the remaining oil by branched-preformed particle gel（BPPG）injection after polymer flooding. The results of micromodel flooding tests show that the remaining oil after polymer flooding stays mainly in the low permeability zones and the corners of the high permeability zones. In the areas swept by polymer flooding，the remaining oil exists in the form of film and beads. The sweep efficiency can be significantly improved by B-PPG flooding because of the dynamic flow diversion function of the viscoelastic B-PPG particles that alternately plug and pass the throats of the pores. B-PPG is capable of adjusting the flow resistances of different permeability zones of a heterogeneous reservoir and preventing the injected water from channeling. An incremental oil recovery of 21.7% was obtained by B-PPG injection after polymer flooding in the sandpacked glass model test. Experimental results in heterogeneous parallel sandpack model showed that polymer slug could not effectively improve the sweep efficiency；while B-PPG exhibited a good performance in adjusting the displacement profile in the heterogeneous model. The substantial amount of the remaining oil in the low permeability zones after polymer flooding could be recovered by B-PPG flooding. In the heterogeneous parallel sandpack test，the enhanced oil recovery of B-PPG flooding after polymer flooding was 22.9%.