This study investigates the critical challenges and corresponding solutions in electronic data forensics within the context of fourth-party payment-based cyber money laundering crimes. As digital finance evolves

the abuse of fourth-party payment platforms for money laundering has become increasingly rampant

making electronic data the cornerstone of conviction and sentencing. However

current practices are hindered by outdated legal frameworks

ambiguous procedural norms

and inadequate mechanisms for ensuring the defendant's right to cross-examination.To address these systemic gaps

this paper first identifies the key application dilemmas of electronic data evidence in such cases. Subsequently

it proposes targeted strategies for rule reconstruction

including the formulation of specialized legal guidelines

standardization of forensic procedures

and strengthening of the defendant's right to cross-examination through technical assistance and improved evidence disclosure.The theoretical significance of this research lies in filling the gap in evidence law scholarship regarding emerging cybercrimes. Practically

it aims to provide law enforcement and judicial authorities with a more robust

fair

and efficient framework to combat fourth-party payment-based money laundering and safeguard financial stability.