The stereospecific property of this asymmetric carbene coupling reaction could be depicted as the cis hydrazone substrate delivered the S-configuration product while the Rconfiguration matched the trans one. We herein proposed an enantio-determined model to elucidate the observed enantioselectivity and stereospecifity. The Pd carbene intermediate A from the cis hydrazone substrate is more preferred to take migratory insertion on the opposite face of the sulfoxide moiety due to the smaller steric hindrance. The stereoenriched alkyl-Pd intermediate allows for the syn-β-H elimination, leading to a pointto-axial chirality transfer and ultimately yielding axially chiral methylenecyclobutanes.