The invention discloses a machinery-solid phase composite connecting device. A blank holder and a female die are arranged from top to bottom, a plate is arranged between the blank holder and the female die, a drive needle is sleeved inside the blank holder, a plurality of spring wafer positioning mechanisms are radially and horizontally distributed in the blank holder, semitubular rivets are vertically arranged in the blank holder and is contacted with the spring wafer positioning mechanisms, and the drive needle, the blank holder, the semitubular rivets and the female die are coaxially arranged. The invention further discloses a machinery-solid phase composite connecting method, accurate positioning and stable driving of the semitubular rivets can be realized through utilizing the spring wafer positioning mechanisms, and process stability and reliability are improved; and solid mixing needles are replaced by the semitubular rivets, rivet force is reduced, joint efficiency is improved, process shrinkage holes through friction stir spot welding are eliminated and machinery-solid phase double connection can be realized at the same time, and static and dynamic mechanics performance of joints are improved. The machinery-solid phase composite connecting method can not only be used for connecting light alloy such as aluminum, magnesium and the like, but also be used for connecting non-metal materials such as composite materials, plastics and the like.