Heterogeneous strengthening effect has been a more and more attractive theory for designing metal matrix composites in recent years. In this paper, a new multiphase reinforced Al composite (Al12Mo+(Al,Zr,Si)+Al2O3)/Al has been prepared through a multi–stage reaction of Al–10ZrO2–5MoSi2 alloy on the basis of Al–10ZrO2, i.e. (ZrAl3+Al2O3)/Al composite, by introducing MoSi2. The strengthening phases, including micro–sized Al12Mo, sub–micron (Al,Zr,Si) and nano–sized Al2O3, are in–situ synthesized, performing attractive strengthening effect. The in–situ synthesized sub–micron (Al,Zr,Si) and nano–sized Al2O3 particles exhibit a net–work distribution, while micron Al12Mo particles act as the node of particle network. Compared with Al–10ZrO2, the Al–10ZrO2–5MoSi2 composite exhibits improved tensile strength at both room temperature (25 °C) and elevated temperature (350 °C). The reaction mechanism and phase evolution procedure have been discussed. This work can be referred in designing new multifarious particles reinforced composites to achieve promotion at material properties.