The contact analysis on the double enveloping hourglass worm gearing is very important to control its efficient contact zone and contact quality. Nevertheless, current meshing analysis under the rigid condition cannot really reflect its tooth-surface contact. In this paper, the contact Finite Element Method is used to analyze the tooth contact of double enveloping hourglass worm gearing under the manufacturing error and the elastic deformation caused by the load. The load sharing among the contact tooth pairs and variations of contact zone are investigated. As compared with the result of rigid analysis, the contact zone is obviously shifted. This analysis method can provide a base for the conjugating control of the double enveloping hourglass worm gearing.