The invention discloses an evaluation method of the maturity of lower paleozoic marine shale organic matter. The evaluation method comprises the steps that (1) samples are collected and screened, wherein a marine shale sample is selected, and the sample is polished or made into a polished section through mechanical polishing equipment or an argon ion polishing machine and other equipment; (2) microscopic components are observed; (3) a conversion formula (EqVRo=1.055*R-0.053) of graptolite dermatosome random reflectance (R) and equivalent vitrinite reflectance (EqVRo) and a conversion formula (EqVRo=0.9096*R
+0.1643) of raw asphalt random reflectance (R
) and the equivalent vitrinite reflectance (EqVRo) are established, wherein R<2>=0.98 in the first conversion formula, and R<2>=0.96 in the second conversion formula; and (4) the maturity of the lower paleozoic marine shale organic matter is evaluated. According to the evaluation method, through microscopic component observation on lower paleozoic marine shale, correct classification and interference elimination, an equivalent relation between the graptolite dermatosome reflectance and the vitrinite reflectance and an equivalent relation between the raw asphalt reflectance and the vitrinite reflectance in the lower paleozoic marine shale are established, and correct evaluation of the maturity of the lower paleozoicmarine shale organic matter is realized.