The thermal conductivity of thermal insulation materials is generally not greater than 0.2 W/(m • K). Because of its good thermal insulation performance-it is widely used in the field of building internal and external walls, roofs and thermal insulation mortar. Fiber reinforced composite thermal insulation foams with different fiber contents (0-3wt% -6wt% and 9wt%) were prepared with phenolic resin as matrix and chopped glass fiber as modified mate rial. The mechanical properties, micro morphology and thermal conductivity of composite thermal insulation foaming materials were analyzed by electronic universal testing machine, SEM and thermal conductivity tester. The results showed that with the increased of fiber content, the compressive strength and tensile strength of fiber-reinforced composite thermal insulation foaming materials increased first and then decreased. When the content of fiber was 6wt%, the compressive strength and tensile strength of composite thermal insulation foaming material reached the maximum, which were 0.241 and ().115 MPa respectively. With the increased of fiber content, the water absorption of composite thermal insulation foaming materials decreased first and then increased, when the content of fiber was 6wt%, the water absorption reached the minimum value of 27.9%. With the increased of fiber content, the brittleness of composite thermal insulation foaming material gradually decreased and the toughness gradually increased, when the content of fiber was 9wt%, the embrittlement rate of composite thermal insulation foaming material was the lowest, which was 1().2%. When the content of fiber was 6wt%, the minimum pore size of composite thermal insulation foaming material was about 3()()/.xm. when the fiber content increased to 9wt%, the number of pores tended to increased, and the size distribution was uneven, with large pores. With the increased of fiber content, the thermal conductivity of composite thermal insulation foams decreased first and then increased. when the content of fiber was 6wt%, the thermal conductivity of composite thermal insulation foaming material reached the lowest value of ().033 W / (m • K). The overall analysis showed that when the content of fiber was 6wt%, the comprehensive performance of fiber-reinforced composite thermal insulation foaming material was the best. [ABSTRACT FROM AUTHOR]