Objective To investigate the biomechanics of a novel injectable calcium phosphate cement (CPC) composited by poly (lactic-co-glycolic acid) (PLGA) combined with double-screw fixation in repairing Schatzker II type tibial plateau fracture, so as to provide the mechanical basis for the clinical minimally invasive treatment. Methods Ten matched pairs of proximal tibia specimens were harvested from 10 elderly cadavers to prepare Schatzker II type tibial plateau fracture model. Fracture was fixed by forcing injection of CPC (experimental group) or autologous cancellous bone (control group) combined with double-screw fixation. The samples underwent axial compression on MTS 858 material testing machine to measure the load-displacement, the maximum load, and compressive stiffness. Results The novel CPC had good injectable property at room temperature, which could fill in bone defect fully and permeated into the surrounding cancellous bone. The average bone mineral density of tibial metaphysis was (0.639 ± 0.081) g/cm2 in the experimental group and (0.668 ± 0.083) g/ cm2 in the control group, showing no significant difference (t=1.012, P=0.331). The maximum load in the experimental group [(4 101 ± 813) N] was significantly higher than that in the control group [(692 ± 138) N] (t=3.932, P=0.001). The compressive stiffness was (1 363 ± 362) N/mm in the experimental group and was (223 ± 54) N/mm in the control group, showing significant difference (t=3.023, P=0.013). Conclusion The novel CPC can effectively restore the biomechanical properties of tibilal plateau in repairing Schatzker II type tibial plateau fracture by means of forcing injection combining with double-screw fixation. It could be used as an effective bone substitute in the clinical application.