In superalloy investment casting, the choice of binder is the most critical core technology. The commonly used traditional binder is a siliceous adhesive. However, this binder chemically decomposes at high temperatures, causing strength loss, thus limiting its development. The aluminium binder has the characteristics of a high melting point and stable structure. By comparing the process parameters of aluminium binder shell materials under different conditions, the technical indicators of aluminium sol in precision casting applications as well as the matching of various technical indicators have been preliminarily determined. By adding a 0.4 wt. % Cr + (III) ion solution to an aluminium sol coating, the problem of the reversible water solubility of the aluminium sol is initially solved. Finally, an aluminium sol-silica sol composite shell with a high-temperature bending strength of 8.4 MPa at 1 500 ℃ was studied.