Based on the Matusita–Sakka equation and the exothermic peaks in the differential thermal analysis (DTA) curves, in silicate glasses with complex crystallization processes containing the precipitation of two or more crystal phases, the effects of particle sizes on the calculations of crystal growth dimensionality and activation energy of crystal growth have been studied in depth. In crystallization processes with two or more crystal phases but one exothermic peak, 0.3 mm is considered as the boundary between the fine and the coarse particles in this type of glass. For glass samples with a particle size less than 0.3 mm, the crystal growth dimensionality is a three‐dimensional mechanism, and EG increases slightly with decreasing particle size. For glass samples with a particle size greater than 0.3 mm, the crystal growth dimensionality is a two‐dimensional mechanism, and EG increases with decreasing particle size. The EG for the fine‐particle starting material is much lower than that of the coarse‐particle starting material. In crystallization processes with two or more crystal phases and two exothermic peaks, 0.104 mm is considered as the boundary between the fine and the coarse particles in this type of glass raw material. For the first peak, in glass samples with a particle size less than 0.104 mm, the crystal growth mechanism is mainly one‐dimensional growth, and EG increases slightly with decreasing particle size. And for glass samples with particle size greater than 0.104 mm, the crystal growth mechanism is mainly two‐dimensional growth, and EG decreases with decreasing particle size. For the second peak, the crystal growth mechanism is mainly a three‐dimensional growth, and EG increases with decreasing particle size.