We investigated the method and techniques of enhancing rice lodging resistance through the analysis influence on bending moment at breaking, bending force and lodging index of stalks in rice under silicon potassium collocation application by using lodgingsusceptible variety‘B You 827’. Results showed that: (1) silicon potassium collocation application could significantly increase the basal internode stem diameter and wall thickness, shortened internode length. In comparison with contrast, internode length decreased about 12.44%-20.80%, as well as, the diameter and wall thickness increased by 2.82%-5.76% and 22.95%-28.57%, respectively with low silicon middle potassium treatment(T₂, silicon fertilizer 300 kg/hm², potash 400 kg/hm²). (2) The cellulose, lignin and ash contents of each basal internode significantly changed under silicon potassium collocation application and with low silicon middle potassium treatment (T₂). As a result, lignin content of basal internode increased by 14.55%, 8.67% and 7.73%, respectively in comparison with contrast. (3) Silicon potassium collocation application could significantly increase the flexural strength of each internode, and reduce lodging index, at the same time. The effect of improving lodging resistance was best with low silicon middle potassium treatment (T₂) in‘B You 827’(bending force was maximum and lodging index was minimum). Researches showed that reasonable ratio of silicon potassium fertilizer (silicon fertilizer 300 kg/hm², potash 400 kg/hm²) could not only significantly increase the basal internode stem diameter and wall thickness in lodgingsusceptible variety‘B You 827’, shortened internode length, improved the flexural strength, but also can increase the basal internode lignification degree, eventually improved lodging resistance; The results also showed that the silicon potassium collocation application by improving physical and chemistry property of stem, can effectively strengthen lodging resistance of rice plants, especially for lodgingsusceptible varieties.