Purpose: Parent involvement is crucial for tailored early intervention programs. The Hanen More Than Words (HMTW) program is a parent-implemented language intervention for autistic children. The current study examined the effectiveness of the HMTW program delivered online among Chinese families. Methods: Using a randomized controlled trial design, 22 Chinese families of autistic children in Hong Kong completed the trial. Baseline and post-intervention assessments were conducted to measure changes in parent-child interaction, parents' use of linguistic facilitation techniques (LFTs), and children's communication skills. Additionally, the influence of parental self-efficacy and parenting stress on treatment outcomes was explored. Results: The intervention group demonstrated significant improvements in parent-child attention synchrony. Although the treatment effect on children's spontaneous communication was not significant, the intervention group showed a larger effect size compared to the controls. The treatment outcomes were mainly influenced by the parents' initial levels of self-efficacy but not by parenting stress. Conclusion: These findings provide preliminary evidence of the effectiveness of the online-delivered HMTW program for Chinese parents of autistic children. Further research involving a larger sample and focusing on long-term effects is needed.