Is Wei Zi's voice in Princess Zhu Huan Ruby Lin's own voice?

No, Wei Zi's voice is Chen Huiqing, a famous voice actor in Taiwan Province Province.

Besides Wei Zi in Princess Pearl, Chen Huiqing also voiced Vivian and Yue Ling in The Curtain of Dreams, Water and Plum Blossom Branding. Therefore, it can be regarded as a female actress in Qiong Yao's drama. Other works that we are familiar with are Shen Xinci (angel) in Qing River's Desperate Love, Xi Chun in Xi Shuo Gan Long 1, Wang Shi (Kara Wai) in Xi Shuo Gan Long 2, Angie Chiu in Qin Shihuang and My Maid, and so on.