Abstract: The development of cotton fiber maturimeter based on SCM technology is carried out.Since SCM has such advantages as high integration and efficiency,reliability,simple in structure,flexible in application and low price,the research work intends to use SCM and realize intelligent and automatic detection of cotton fibre maturity in accordance with the principle of polarized light.The optical-electronic signal maturity of cotton fiber is output by optical-electronic circuit,and then analog to digital conversion is done by A/D converter,and finally,calculation of parameters on maturity is conducted and relative deviation of output is given by comparing with standard value.According to empirical data and measured values on maturity of some cotton varieties,the relationship between intensity of transmission and maturity index,relative intensity and correction coefficient of fiber number are investigated.