i am a chinese citizen residing in the philippines since birth. I want to obtain a chinese passport

If you don’t have Philippines passport or any other passport, you can apply for a Chinese passport. You need to prepare these materials containing the application form, 2 passport-style photos taken recently, birth certificate and charge receipt issued by NSO, and non-Philippines nationality statement issued by Philippines immigration ofice, as well as your residence permit in Philippines.
And then submit the application to the embassy of PRC to apply for it.