This paper focuses on the effect of temperature on the out-of-plane compressive properties and failure mechanism of carbon fiber/epoxy composite pyramidal truss cores sandwich panels(CF/CPTSP). CF/CPTSP with novel reinforced frames are manufactured by the water jet cutting and interlocking assembly method in this paper. The theoretical analysis is presented to predict the out-of-plane compressive stiffness and strength of CF/CPTSP at different ambient temperatures. The tests of composite sandwich panels are performed throughout the temperature range from -90℃ to 180℃. Good agreement is found between theoretical predictions and experimental measurements. Experimental results indicate that the low temperature increases the compressive stiffness and strength of CF/CPTSP. However, the high temperature causes the degradation of the compressive stiffness and strength. Meanwhile, the effects of temperature on the failure mode of composite sandwich panels are also observed. This paper focuses on the effect of temperature on the out-of-plane compressive properties and failure mechanism of carbon fiber / epoxy composite pyramidal truss cores sandwich panels (CF / CPTSP). CF / CPTSP with novel reinforced frames are manufactured by the water jet cutting and interlocking assembly method in this paper. The theoretical analysis is presented to predict the out-of-plane compressive stiffness and strength of CF / CPTSP at different ambient temperatures. The tests of composite sandwich panels are performed throughout the temperature range from -90 ° C to 180 ° C Good agreement is found between theoretical predictions and experimental measurements. Experimental results indicate that the low temperature increases the compressive stiffness and strength of CF / CPTSP. However, the high temperature causes the degradation of compressive stiffness and strength. , the effects of temperature on the failure mode of composite sandwich panels are also observed.