In recent years, phase separation glass has attracted extensive attention because of its unique structure and excellent properties. But its mechanism of phase separation on glass remains insufficient clear, especially, the influence of recombination time on structure and properties is unclear. Here, strengthened P₂O₅-Al₂O₃ glass with SiO₂-Na₂O high-silicate glass particles as the second phase was prepared by melting-quenching method combined with pneumatic atomization and mechanical stirring. The relationship between structure and mechanical properties of the glass was investigated by varying the recombination time. Experiment results showed that Young's modulus of the heterogeneous composite glass was higher than that of the P₂O₅-Al₂O₃ glass. Young's modulus of the sample firstly increased and then decreased with the recombination time increasing from 10 s to 8 min. The highest Young's modulus of 80.7 GPa was obtained at recombination time of 6 min, which was increased by 18% as compared with the P₂O₅-Al₂O₃ glass. Introducing SiO₂-Na₂O high-silicate glass particles not only formed the second phase in the matrix glass, but also changed the structure of the P₂O₅-Al₂O₃ glass. As the recombination time increases from 10 s to 6 min, coordination number of phosphorus in heterogeneous composite glass network gradually increases, while amount of non-bridging oxygen in the glass network gradually decreases, resulting in a gradual increase in network cross-linking. However, when the recombination time is more than 8 min, it is not conducive to network crosslinking. Therefore, development of heterogeneous composite glass can provide a new route for the preparation of glass materials with good damage resistance.