Fred Onyedinma had given Wycombe a shock lead after Gareth Bale wasted a couple of early chances, but the Real Madrid loanee equalised in first-half injury time to send Spurs in level.
The Chairboys battled valiantly, but late goals from Harry Winks and Tanguy Ndombele sent Jose Mourinho’s Spurs through to the FA Cup fifth round.
Mourinho made 10 changes to his side, with Bale afforded a rare start while the likes of Harry Kane and Heung-min Son were left on the bench.
Bale wasted two presentable chances early on, and Wycombe made Spurs pay as Onyedinma handed the Chairboys a shock lead after 25 minutes.
Uche Ikpeazu's cross was not cleared by Davinson Sanchez and it fell to Onyedinma, who fired home.
Spurs immediately went looking for an equaliser, with Moussa Sissoko and Japhet Tanganga both hitting the woodwork - but Wycombe could not hold out for the half-time whistle.
In the first minute of injury time, Bale broke the offside trap to ghost onto a Lucas Moura cross and deftly flick a volley home to send Spurs into the interval level.
Mourinho responded by sending on Pierre-Emile Hojbjerg as a half-time substitute, and Spurs ramped up the pressure as the chances came thick and fast.
The Spurs boss piled on the pressure with Kane, Son and Tanguy Ndombele all coming on, and the extra quality told as Harry Winks finished from outside the box with five minutes remaining after Kane was denied.
Wycombe immediately went in search of an equaliser, but were quickly caught on the counter - and Ndombele finished a clinical team move to wrap up the game before adding an other deep into injury time.
Spurs will now face a trip to Everton in the fifth round. Though they beat Wycombe by three goals, the scoreline did not tell the whole story - and Spurs will need to improve at Goodison Park if they are to stay in the competition.
