The Japanese was already the most successful all-around gymnast in history with four gold medals, and he extended that record in the men's final on Thursday.
Uchimura's combined score of 91.965 saw him finish comfortably ahead of Britain's Max Whitlock, who claimed silver with a score of 90.473, and countryman Yusuke Tanaka in third.
Whitlock's second-place finish caps a fine end to a topsy-turvy week, which started when he originally failed to reach the final because only two gymnasts per national federation can participate and he had ranked below team-mates Daniel Purvis and Nile Wilson in qualification.
However, he was handed a reprieve when Wilson withdrew on Wednesday because of a wrist injury.
Whitlock immediately made the most of his second chance as he top scored on the pommel horse to take the early lead.
Uchimura soon centre stage, though, and he capped off victory with an exhilarating performance on the horizontal bar that drew a rapturous round of applause from the crowd in China.
He now becomes just the third gymnast to win five world titles in the same event, joining Jury Chechi (rings) and Svetlana Khorkina (uneven bars).
Much like Whitlock, Tanaka was the beneficiary of good luck. Following an inquiry, his difficulty score on the pommel horse was increased by 0.30 points.
Having narrowly beaten Oleg Verniaiev of Ukraine by 0.151 points, the decision proved the difference between him taking bronze and finishing outside the medal positions.