A substrate bonding method includes: providing a first and a second substrate; forming, on the first substrate, a first metal micro-bump array including first metal pillar(s) formed on the first substrate and first metal nanowires formed thereon and spaced apart from each other; forming, on the second substrate, a second metal micro-bump array including second metal pillar(s) formed on the second substrate and second metal nanowires formed thereon and spaced apart from each other; pressing the first substrate onto the second substrate, such that the first and second metal micro-bump arrays are positioned and staggered with each other, forming a physically interwoven interlocking structure between the first and second metal nanowires; applying a filling material between the first and second substrates; curing the filling material to form a bonding cavity; and then performing confined heating reflux on the first and second metal micro-bump arrays in the bonding cavity.