Sawdust-magnesium oxychloride cement composite (SMOCC) is a kind of new building material incorporating magnesium oxychloride cement as cementitious material, sawdust as filling material, mixed with appropriate proportion of modifiers, and pressed and molded under 5 MPa pressure. In order to investigate the basic mechanical properties and damage evolution of SMOCC, cubic compression, cubic split tensile and prism compression tests at different loading rates were carried out. At the same time, based on the experimental results, the statistical damage constitutive models of SMOCC under different loading rates were established by using Lognormal and GaussAmp statistical distribution functions, respectively, combined with the equivalent strain principle. The results show that the cubic compressive strength, splitting tensile strength, and elastic modulus increase with the increase of apparent density. The peak strain and peak stress of SMOCC decrease with the increase of loading rate. At lower loading rates, the internal defects and micro-cracks of SMOCC develop more fully, the concave of the initial compaction section of the stress-strain curve is more obvious, and the brittle failure of the material is improved. Compared with the Lognormal statistical distribution function, the constitutive model established by the GaussAmp statistical distribution function is able to better describe the uniaxial compressive mechanical behavior and damage evolution process of SMOCC. The research results can provide a theoretical basis for the design and application of SMOCC.