Abstract: The paper presented a new structural form of the floor, M-shaped steel truss floor, to improve the thermal insulation and mechanical properties of the floor. Two M-shaped steel truss floors with different steel thicknesses were designed and static test was carried out. Based on the characteristics of M-shaped steel and combined with the existing theory, the equivalent calculation formula of M-shaped steel truss floor and the calculation formula of the cracking load and bearing capacity of the corresponding floor were proposed. The test results and theoretical calculation results showed that the overall stiffness and bearing capacity of the floor were large enough, and when the uniformly distributed load reached the designed of load value, the mid-span deformation of the floor was so far less than the requirements of Code for Design of Concrete Structures(GB 50010-2010) that it had a large safety reserve; the floor section conforms to the assumption of plane section; the error between theoretical calculation results of peak load and test results was small. The equivalent calculation formula and bearing capacity calculation formula of steel were reasonable and effective.