The White Ferns bowlers, led by legspinner Amelia Kerr's 3 for 35, helped skittle the hosts for 147.
In reply the New Zealand batters had little trouble hunting down the target with 26 overs to spare.
Sophie Devine, who scored a century in the opening match, continued her fine form from the first ODI, hitting a 48-ball 62 with eight fours.
Pakistan elected to bat first, but struggled from the outset, losing Ayesha Zafar in the seventh over for 2. Opener Nahida Khan and captain Bismah Maroof brought Pakistan back into the game with a 46-run, third-wicket partnership of 75 balls, the second-highest stand of the match.
The middle order, though, capitulated against Kerr and offspinner Leigh Kasperek, losing 5 for 39 to slump to 113 for 7. Sana Mir hit 31 off 46 balls, but Pakistan lost their last three wickets without a run.
In reply, the White Ferns captain Suzie Bates and Devine struck an 80-run opening stand in just 12.5 overs. Amy Satterthwaite struck 25 off 34 balls. The Pakistan offspinner Javeria Khan took 2 for 6 in her three overs.
New Zealand won the first game by just eight runs after a batting collpase by the hosts saw them lose their last five wickets for just 15 runs.