The “bandwagoning-balancing-hedging” trichotomy elaborated by the existing international relations theories could not fully explain the EU’s taking-side strategy in the trilateral game among China, the US and the EU. By walking through the history of China-EU economic and trade negotiations, it is found that the EU actually implemented a so-called “power-borrowing strategy” and usually borrowed power from the US. Three modes of power-borrowing have been identified when the EU borrowed power from the US, namely, the EU and the US joining hands in projecting power over China, the EU profiting from the tensions between China and the US, and the EU demanding equal treatment from China as already been extended to the US. The fact that the EU power-borrowing strategy has been somehow effective is largely due to the strategic competition between China and the US. In the trilateral game among China, the US and the EU, in order to effectively respond to the EU’s “power-borrowing strategy”, China needs to be alert to the co-existence of the “three chessboards” in the China-US-EU strategic triangle, that is, the China-US chessboard, the China-EU chessboard and the US-EU chessboard.