In 1938 and 1939 Chinese paleontologist Mei Nien Bien collected material from the Dark Red Beds of the lower Lufeng Formation that included the nearly complete jaw and partial skull of a relative of the armored dinosaur Scelidosaurus, though it was not described as such until 2001.

In 2001, Chinese paleontologist Dong Zhiming described this specimen, IVPP V 9612, as a new member of the family Scelidosauridae, Bienosaurus lufengensis.

The genus name is in honor of the collector Bien and combines with it the Ancient Greek word σαυρος (sauros) for "lizard", while the specific name is for the Lufeng Basin where the holotype skull was found.

[2] As it comes from the lower Lufeng Formation, Bienosaurus would be one of the earliest known ornithischians, living in the Hettangian to Sinemurian of the Early Jurassic.

As well, due to the incomplete and fragmentary nature of the material, it could not be distinguished from other thyreophorans and was thus dubious, with the possibility that it could represent the same taxon as Tatisaurus from the same formation.