Bingham, who had a 104 break to level in frame two, took the £10,000 first prize - amateur Li picks up £5,000 - and 2,000 ranking points after surviving a scare at 3-2 down.
Li was 60-0 up in that sixth frame but the Essex cueman came back with breaks of 49 and 25 to earn a decider.
Li had an 83 clearance in frame four to go 3-1 up but Bingham responded in the next frame with an 81.
Bingham also won by the odd frame against Tom Ford, who he has now beaten four times in five meetings, in the semi-finals.
Li impressed in beating Robert Milkins in the last four, compiling breaks of 51, 50, 52, 87 and 58.
Bingham won APTC1 in June to secure his spot in the PTC Finals, while Li has also qualified with his run to the final.
The PTC consists of 13 minor-ranking events before the Finals, which is a ranking tournament and features the top 25 players in the Order of Merit who have played at least five events - two in the UK and three in Europe - as well as the winners of all three Asian events and the top four from the Asian Order of Merit who have not won one of those three events.
Stephen Lee, who is currently suspended pending an investigation into suspicious betting patterns, won Asian PTC2.
The three other players who are guaranteed to qualify for the Finals from the Chinese events are Ding Junhui, Robert Milkins and Tom Ford.