塔吊的(de)工作(zuo)原理是起重(zhong)(zhong)(zhong)機械通過起重(zhong)(zhong)(zhong)吊鉤(gou)或其它取物裝(zhuang)(zhuang)置(zhi)起升或起升加移(yi)動重(zhong)(zhong)(zhong)物。起重(zhong)(zhong)(zhong)機械的(de)工作(zuo)過程一(yi)般包括(kuo)起升、運(yun)行、下(xia)降及返回原位等(deng)步驟。起升機構通過取物裝(zhuang)(zhuang)置(zhi)從取物地(di)點把(ba)重(zhong)(zhong)(zhong)物提起，經(jing)運(yun)行、回轉或變幅機構把(ba)重(zhong)(zhong)(zhong)物移(yi)位，在設(she)定(ding)的(de)地(di)點下(xia)放重(zhong)(zhong)(zhong)物后返回到原位。

常見的(de)(de)(de)驅(qu)動裝置有(you)電力驅(qu)動、內燃機(ji)驅(qu)動和人力驅(qu)動等。電能是清(qing)潔、經濟的(de)(de)(de)能源，電力驅(qu)動是現代起(qi)重(zhong)機(ji)的(de)(de)(de)主要驅(qu)動型式(shi)，幾(ji)乎所(suo)有(you)的(de)(de)(de)在有(you)限范圍內運行的(de)(de)(de)有(you)軌起(qi)重(zhong)機(ji)、升降(jiang)機(ji)、電梯(ti)等都采用電力驅(qu)動。

對于可以遠距離(li)移動(dong)(dong)的流動(dong)(dong)式起(qi)(qi)(qi)重(zhong)(zhong)(zhong)機(ji)(ji)(如汽車起(qi)(qi)(qi)重(zhong)(zhong)(zhong)機(ji)(ji)、輪胎起(qi)(qi)(qi)重(zhong)(zhong)(zhong)機(ji)(ji)和(he)(he)履帶起(qi)(qi)(qi)重(zhong)(zhong)(zhong)機(ji)(ji))多(duo)采用(yong)內燃(ran)機(ji)(ji)驅動(dong)(dong)。人力驅動(dong)(dong)適用(yong)于一些輕(qing)小起(qi)(qi)(qi)重(zhong)(zhong)(zhong)設(she)(she)備，也用(yong)作某些設(she)(she)備的輔助、備用(yong)驅動(dong)(dong)和(he)(he)意外(或事故(gu)狀態)的臨時動(dong)(dong)力。