The invention relates to the technical field of display, in particular to a method for manufacturing a substrate, the substrate and a display device and aims at solving the problem that in the prior art, when a signal line is formed, due to the mechanical damage of the etching process to the signal line, the signal line is in a short circuit or an open circuit. According to the embodiment, when a needed metal pattern is manufactured, the needed metal pattern can be formed without adopting the etching way, a photoresist layer is firstly deposited and then patterned, a photoresist pattern is formed and utilized for blocking, a metal film layer is deposited, finally the photoresist pattern is stripped, and the needed metal pattern is kept. Therefore, the manufacturing process is simplified, the mechanical damage caused by the etching process is avoided, and the problem that the short circuit or open circuit of the signal line caused by the etching process is avoided.