Differences of the particle matching of cementitious materials can affect the voids between cementitious materials, thereby influencing the strength properties and durability of concrete in this work, the laser particle size analyzers analyze the size distribution of cement, slag and fly ash. The workability of paste and concrete is characterized by fluidity, slump, and expansion, and the particle matching of fly ash and slag is evaluated. The chemical composition of hydration products of hardened paste is analyzed, and concrete strength is tested. Based on the results of the effect of particle matching of cementitious materials on shotcrete performance, the shotcrete mix ratio is optimized. The results show that, when slag: fly ash is 3:1, the workability is the best, showing good mechanical properties. When the ratio of slag to fly ash is 1:3, the workability of paste is the worst, and the compressive strength of the specimens is the lowest. Similar results were obtained for concrete specimens with the same particle matching. Considering the results of flowability and strength tests, when the ratio of slag to fly ash is 1:1, the particle matching of cementitious materials is better, which can be considered as the optimal mix ratio.