Coir fiber concrete has better thermal performance than ordinary concrete,but it is not suitable for the enclosure structure material due to heavy self-weight.Holes can be increased inside the coir fiber concrete solid block to reduce the weight and lower the thermal conductivity meeting the requirements of compressive strength.ANSYS Fluent is used to analyze the influence factors on the thermal performance of coir fiber reinforced concrete hollow blocks when the number of holes,the ratio of hole length-to-width and the ratio of hole are considered as single factor and multiple factor variables,respectively.ANSYS Workbench is used to investigate whether the hollow block with the best thermal performance meets the design strength requirements of MU7.5,so as to obtain the best hole type.The results show that when the number of holes is 2,the ratio of hole length-to-width is 11:1,and the ratio of hole is 30%,the equivalent thermal conductivity is the lowest which is 0.273 W/(m·K)and 59.33%lower than that of solid coir fiber concrete,and the compressive strength is 9.77 MPa meeting the requirements of the design strength MU7.5.