A safety belt buckle includes a base, a latch, two positioning members, and two elastic members. The base is formed by two symmetrically combined cases, wherein each case includes a first metal core partially clad in a first insulating layer. The latch includes a second metal core, a second insulating layer, and a tongue adapted to insert into a chamber of the base. The two positioning members are pivotally provided on the base and partially located in the chamber. When each positioning member is moved to the first position, a stopper thereof confines the tongue in a locking position to prevent the latch from being separated from the base; when each positioning member is moved to the second position, the stopper thereof is away from the tongue, allowing the latch to be disengaged from the base. The two elastic members push the positioning members toward the first position.