Antiretroviral drug resistance has become a major threat to the adequate management of human immunodeficiency virus (HIV) infection, but little attention has been paid to the spread and evolution of drug-resistant strains in the family. Here, we described a case of transmitted as well as acquired HIV drug resistance among a father, mother and infant. Epidemiological data were obtained retrospectively. Drug resistance mutations (DRMs) of three patients were tested using a validated In-house Sanger-based sequencing (SBS) method and the Vela next-generation sequencing (NGS) platform. Gene evolution analysis was also performed. According to the epidemiological history and phylogenetic data, in late pregnancy of the mother, the infant's father transmitted HIV-1 to her, and then the mother to the baby, leading to the transmission of V106I as a common mutation of three persons. The mutant frequency was 99.57% (father), 95.38% (mother) and 99.73% (infant), respectively. Mother also acquired K101E (41.03%), K103N (27.56%) and minor mutation of V106M (4.30%) after improperly discontinuing antiretroviral regimen of lamivudine (3TC), tenofovir (TDF) and efavirenz (EFV). Such acquired mutations increased the drug resistance scores on non-nucleoside reverse transcriptase inhibitors (NNRTIs) doravirine, EFV, etravirine, nevirapine and rilpivirine from 10, 0, 10, 10 and 10 to 65, 135, 25, 150 and 55, respectively. Therefore, sexually transmitted diseases, especially DRMs of HIV-1 in families, are of concern and draw attention to the need for enhanced drug-resistance prevention efforts, and accurate surveillance by more sensitive methods in complicated cases.