Yanez called on other members of the military to defect. The high command's web page lists him, along with a photo, as the air force's head of strategic planning.
On its Twitter account, the high command accused the general of treason.
The video came as opposition supporters were set to protest nationwide in a bid to keep up the pressure on Maduro after Washington recognized Guaido as the legitimate president and issued potentially crippling sanctions that are likely to further weaken the OPEC nation's struggling oil industry.
Yanez is the first active Venezuelan general to recognize Guaido since he proclaimed himself president in January.