Abstract: In order to explore the mechanism of exogenous silicon regulating the saline alkali tolerance of rice in cold saline alkali land in Western Heilongjiang Province, Suigeng 306 was used as material. Two cultivation methods, pot planting in saline alkali soil and conventional planting in saline alkali paddy field, were selected to study the effect of 2.0 mmol·L^-1 exogenous silicon on the content changes of major inorganic ions in rice leaves, stems and root organs, to clarify the absorption, transportation and redistribution of major ions in rice plants by exogenous silicon under saline alkali conditions. The results showed that under saline alkali stress, the addition of exogenous silicon could significantly reduce the content of Na⁺ ions in rice plants, weaken the antagonistic effect between Na⁺ and K⁺, Ca²⁺ and Mg²⁺ ions, and effectively regulate the transport ratio and transport selection ratio of major inorganic ions from root to stem and stem to leaf. The application of exogenous silicon has a positive effect on the physiological and ecological health development of rice in cold saline alkali land.