The present invention discloses one kind of combinable robot article and its constituted foot unit. The robot article includes one motor, one reducing gear unit, one spur gear and turning reducer, one photoelectronic coder and one potentiometer. The foot unit includes one foot terminal, one shank article, one thigh article, a hip article, one upper frame and one lower frame. The robot article with rotating function may be combined with similar articles to constitute robot of different forms, such as walking robot, industrial mechanical arm, wheel type robot, etc. The robot with the said article structure has no structural redundancy, relatively simple design and machining, and powerful expansion capacity of altering article combining mode to adapt to different work environments and tasks.