This paper present a realization of hi-resolution timer class, based on multithread technique, in the BCB IDE. Utilizing of the class, derived from TThread class of VCL and integrated with Windows message mechanism, achieved a general timing-error < 0.5ms. The class is provided of advantages such as multiple timers-single object managing, work state of timer-thread adjusting, callback mode controlling, as well as more convenient and more customizable than traditional windows System Timer and Multimedia Timer. Thus it could be applied in projects with relatively time-critical requirement, e.g. industrial control, multimedia app development and realtime signal sampling & processing.