Top seeds and world champions Zhang Nan and Zhao Yunlei will take on number two pair Xu Chen and Ma Jin for the title at Wembley Arena on Friday after hard-fought semi-final wins.
Both pairs needed to come from behind with Zhang and Zhao extended by Denmark's Joachim Fischer and Christinna Pedersen before prevailing 17-21 21-17 21-19 in 82 gruelling minutes.
Xu and Ma needed to hold out in a nervy second game after losing a tight opener against All England champions Tontowi Ahmad and Liliyana Natsir before winning 21-23 21-18 21-13 in 75 minutes.
The defeat for Ahmad and Natsir means that for the first time in Olympic history Indonesia will not claim at least one Badminton gold. They were the country's last representatives after defeat for men's pair Mohammad Ashan and Bona Septano earlier in the day.
The semi-final line-up for the women's Singles competitions was completed on Day 6.
Europe's top player, fifth seed Tine Baun, lost to India's fourth-seeded Saina Nehwal.
The other three players in the last four are all Chinese.
Top seed Wang Yihan brushed off Cheng Shiao Chieh 21-14 21-11, Wang Xin avoided an upset to beat Thai Intanon Ratchanok 17-21 21- 17 21-14 and Li Xuerui overcame Hong Kong's Yip Pui Yin 21-12 22-20.