In this study, molybdenum dithiocarbamate (MoDTC) coatings were fabricated on 304 stainless steel substrates via an electrodynamic spraying process with the aim to clearly understand the evolutionary process from MoDTC to MoS2 during contact sliding. Experiments were performed using an in-situ tribo-tester equipped with Raman spectroscopy to continuously monitor the chemical state of the wear track. The tribochemical reaction and removal process of MoDTC were assessed, and the evolution process of MoDTC was determined systematically. Additionally, it was determined that the tribological performance of the MoDTC coating was dominated by a tribochemical reaction at the microscale and by surface topography at the macroscale. •The tribochemical mechanism of MoDTC as a solid lubricant was first revealed.•Chemical evolution was monitored by an in-situ tribo-tester.•Tribochemical reaction affected by temperature and substrate roughness was studied.•Tribological performance of the MoDTC coating was highly dependent on scale.•The MoDTC coating exhibited low COF of 0.07 under severe conditions.