The paper aims to study effects of temperature, humidity and UV aging on properties of delignified and unde-lignin pulp molding materials, to quantitatively compare the differences in mechanical properties of the two materials under different factors. With waste paper pulp as raw material, pulping, delignification, wet forming, hot pressing and other processes were carried out to obtain two kinds of pulp molding materials: delignification and non-de-lignin; different temperature and humidity and ultraviolet aging environments were simulated to test changes in the physical and mechanical properties of two pulp molding materials. Under the same conditions, the tensile strength and flexural strength of delignified materials were higher than that of unde-lignin materials; the tensile strength, elastic modulus and flexural strength of the two materials decreased greatly with the increase of water content; at 20 °C and water content of 0~40%, the tensile strength of the delignified material was reduced by 45 MPa, and the tensile strength of the unde-lignin material was decreased by 35 MPa. At 0 °C and water content of 0~40%, the bending strength of the delignified material was reduced by 70 MPa, and the bending strength of the unde-lignin material was reduced by 62 MPa; when the water content was less than 20%, the tensile properties and bending properties of lignin materials were more susceptible to temperature; although the tensile properties and bending properties of the two materials were continuously reduced with the extension of UV aging time, the degree of influence was much less than the temperature and humidity. Humidity has the greatest influence on the mechanical properties of the material, followed by temperature and UV aging. Removal of lignin is beneficial to improve the mechanical properties and UV aging resistance of the pulp molding materials.