The reconstruction of Beijing Electron Positron Collider (BEPCII) is a great national scientific project. To install and adjust B magnet
Q magnet
S magnet and vacuum in a support accurately
a laser tracker is adopted in the process of pre-assembly and pre-alignment of BEPCII. Transforming instrument reference frame into B magnet reference frame by coordinate-transformation represents more visual relations among all parts. The survey precision and accuracy are confirmed by error analyses.