SMT solver is an important system software. Therefore, bugs in the SMT solver may lead to the function failure of software relying on it and even bring security incidents. However, fixing bugs in the SMT solver is time-consuming because developers need to spend a lot of effort in understanding and finding the root cause of the bugs. Although many studies on software bug localization have been proposed, there is no systematic work to automatically locate bugs in the SMT solver. Therefore, this study proposes a bug localization method for the SMT solver based on multi-source spectrums, namely SMTLOC. First, for a given bug in the SMT solver, SMTLOC proposes an enumeration-based algorithm to mutate the formula that triggers the bug by generating a set of witness formulas that will not trigger the bug but has a similar execution trace with the formula that triggers the corresponding bug. Then, according to the execution trace of the witness formulas and the source code information of the SMT solver, SMTLOC develops a technique based on the coverage spectrum and historical spectrum to calculate the suspiciousness of files, thus locating the files that contain the bug. In order to evaluate the effectiveness of SMTLOC, 60 bugs in the SMT solver are collected. Experimental results show that SMTLOC is superior to the traditional spectrum bug localization method and can locate 46.67% of the bugs in TOP-5 files, and the localization effect is improved by 133.33%.