Using heat conduction equation, the temperature distributions around pits on multi-crystalline silicon surface are calculated under different boundary conditions during etching reaction. The simulation results show that the solution temperature of 15 ℃ controlled by cooling measures can result in an obvious temperature difference between the pits bottoms and multi-crystalline silicon surfaces. This difference is helpful to reduce the pits opening size as well as increase the pits depth. On the other hand, etching the multi-crystalline silicon surface without temperature control will make little temperature difference between the pits bottoms and multi-crystalline silicon surfaces, which produces the trap pits with the shallow and large opening. Silicon surfaces are textured under different temperature conditions in the experiment. Scanning electron microscope (SEM) image of experimental sample surface etched under the low-temperature condition shows the high-density distributions of trap pits with large pits depth and small opening. The experimental results can match the theoretical prediction well.