Abstract: A study for roof structure optimization of a squat silo was carried out in this paper for the project of ShunDe Grain Industrial Park.The radial force and circumference force of conical shell at different inclinations were calculated and compared by numerical simulation and theoretical calculations.Results showed that the circumference force of the upper part of conical shell was compressive stress and the lower part was tensile stress;the radial force was compressive stress;the circumference force calculation results of theoretical calculation method were not accord with the practice,and the theoretical calculation methods in the relative code should be modified;the circumference force and radial force of the conical shell increased with accelerated change rate with the decrease of inclinations;it's proposed that the degree of the silo roof shell should be controlled between 18°to 25ånd the lower tensile region of the conical shell and the outer-ring beam should be provided with tensile steel bar based on calculation results.The research result is beneficial for roof optimization design of RC squat silo.