To study the response characteristics of LiF detectors to proton fluence rate and energy, and to observe the thickness effect of the detector.Protons were generated by an accelerator. Proton energy was changed in two ways, i.e. changing the accelerator energy directly, or using detector stacks to absorb the proton energy. The incident proton energy on each chip of detector stacks was calculated according to proton range in LiF.The response of the detector to proton fluence rate was almost constant; when proton energy was above 9 MeV, the response of the detector to proton energy was constant (less than 10% errors). When proton energy was below 9 MeV, the response reduced gradually with the decrease of proton energy. Thickness effect for LiF thicknesses of 0.4mm and 0.8mm was not obvious.The homemade LiF detector is suitable for measurement of space radiation dose. When proton component (below 9 MeV) was abundant in radiation field, the decrease of the relative thermoluminescence efficiency should be taken into consideration.