To solve the problem of massive piling and overcome the difficulty of treatment for waste wind turbine blade (WTB), the recycled WTB (rWTB) fiber was obtained by mechanical crushing, and the influence of rWTB fiber content (0%, 10%, 20% and 30%, mass fraction) on the mechanical properties and frost resistance of concrete were investigated. The economic and environmental benefits of the reuse of waste WTB in concrete were discussed. It is revealed that adding 10%, 20% and 30% rWTB fiber significantly increase the flexural strength and splitting tensile strength of concrete, the flexural strength of concrete increases by 2.8%, 2.8% and 11.1%, and the splitting tensile strength increases by 56.3%, 68.8% and 40.6%, respectively. The freeze-thaw cycles of 20% rWTB fiber concrete are 75 times, far exceeding that of plain concrete (25 times), illustrating the highly improved frost resistance. However, the compressive strength and frost resistance decrease with excessive addition of rWTB fiber (30%), and the water absorption increases obviously. Compared with the incineration treatment, adding 20% rWTB fiber can reduce the cost of concrete by 69.2 yuan/m3 and the CO2 emission by 0.04 t/m3.