Objective: To develop a communication prompt based on dignity therapy to facilitate effective conversations between patients with haematologic neoplasms and their family caregivers and to improve the programme and preliminarily explore the benefits and challenges of family participatory dignity therapy (FPDT).; Methods: A mixed-methods approach was applied to develop and revise the programme. The FPDT was developed and validated using the Delphi survey, and its further improvement was explored with a simple one-group pre- and post-trial and semi-structured in-depth interviews.; Results: Most of the FPDT items were endorsed by experts and patient-family dyads. The Content Validity Index was 93.6% in the first round of the Delphi survey and 100% in the second round. The "hope level," "spiritual well-being" and "general health" scores of pre- and post-testing increased from 33.60 ± 4.30 to 37.70 ± 5.10 (t = 3.99, p = .003); from 30.30 ± 3.65 to 38.80 ± 7.29(t = 4.13, p = .003); and from 41.67 ± 8.78 to 53.33 ± 8.05 (t = 3.50, p = .007) respectively. The qualitative data also indicated that the project was meaningful and well received.; Conclusions: We showed that FPDT was a valuable and feasible means of improving communication between patients with haematologic neoplasms and their family caregivers in China by raising the hope level and spiritual well-being and promoting general health.