Red blood cell (RBC) deformability plays an important role in angiocardiopathy. In this paper, the Yin and Yang of low intensity laser irradiation (LIL) and RBC were defined according to the time theory of Yin and Yang, and the biological information model of the effect of LIL on RBC deformability was put forward in terms of Yin-Yang parallel principle and cellular collective phototransduction theory as following: For LIL at dose 1, cold color such as green, blue or violet reduces RBC deformability, and hot color such as red, orange or yellow improves RBC deformability; for LIL at dose 2, hot (cold) color reduces (improves) RBC deformability;……; the effects of LIL at dose 2n is the same as the ones at dose 2; the effects of LIL at dose 2n+1 is the same as the ones at dose 1. This model was verified by many experimental data. The initial state effect of RBC on LIL effects and the union effects of LIL and drug on RBC deformability were also discussed in terms of the cellular collective phototransduction theory.