Objective: This study aimed to explore the acceptability and feasibility of Cognifit, an innovative digital gamified cognitive training method, in improving cognitive late effects among preschool children with cancer, and to describe the determinants of its implementation. Method: A single-group, prospective, embedded mixed-methods design was employed to measure cognitive changes following training and evaluate system performance. Quantitative assessment tools include the Behavior Rating Inventory of Executive Function – Preschool Version (BRIEF-P), Sustained Attention Test, Working Memory Test, Pediatric Quality of Life Inventory Version 4.0 (PedQL™ 4.0), and System Usability Scale (SUS). After completing the training, caregivers underwent interviews to assess the acceptability and feasibility of Cognifit. Result: A total of 18 preschool-aged children with cancer and their caregivers agreed to participate, with 2 of them dropping out midway . Quantitative descriptive data indicated that executive function and quality of life appeared to have improved, suggesting the feasibility of large-scale future implementation. Qualitative semi-structured interviews revealed thatdespite facing challenges such as regular participation and cultural misunderstandings, caregivers generally held a positive attitude toward the Cognifit digital game-based cognitive training. Conclusion: Our study confirmed the feasibility and acceptability of the Cognifit digital gamified intervention for preschoolaged children with cancer and their caregivers. The study underscores the importance of adapting digital gamified interventions to better suit vulnerable populations such as preschool-aged children with cancer and proposes corresponding improvement recommendations. Future research should explore modifications to the intervention protocol while conducting large-scale, multicenter randomized controlled trials to evaluate the effectiveness of the intervention.