First, we introduce the diagnostic space, treatment space and some medicinal vectors, and propose the matrix mechanics of pharmacology, and corresponding linear algebra and quantum medicine. Second, we discuss nonlinear biomechanics, which includes chaos, fractal and soliton, etc. It is related to entropy decrease. Lorenz model may be applied to describe the model of brain. Third, based on the Chinese traditional culture, we propose three principles of self-cultivation and health: health must first nourish self-heart, life should be a combination of movement and peace, and the body-mind-spirit union. Finally, we research the preliminary epidemic equations of COVID-19, and discuss their meaning.