Kemar Roofe scored on the rebound to open the scoring after Liam Sercombe's effort had hit the woodwork.
Sercombe secured the points in stoppage time when he broke through on goal and calmly beat the goalkeeper.
The visitors best effort came through a Matthew Bates glancing header that flew just wide.
Victory keeps the U's in League Two's automatic promotion places but with fourth-placed Bristol Rovers also winning the gap is just a point while defeat for Pools keeps them in 16th.
Oxford United ended a run of two games without a win as they defeated Hartlepool United and maintained their push for automatic promotion.