Recently, sustainable fabrication of hygiene-related textiles combining bioactive substances and cleaner production technique has been increasingly emphasized. This research introduces an efficient ultrasonic-assisted electrostatic co-deposition strategy for colouristic, antibacterial and ultraviolet (UV) protective cotton fabric with trimethyl chitosan (TMC) – a chitosan derivative, and Glochidion ericarpum Champ leave extract (GECLE). Results reveal that TMC significantly promotes the adsorption of GECLE to cotton by creating additional cationic binding sites. Based on Pesudo first-/second-order kinetic models, chemisorption is verified as the dominant mechanism triggered by the electrostatic interaction between TMC and GECLE. Indicated by adsorption rate constant k, the efficiency under ultrasound is enhanced by 13.5 % (60 °C) and 23.8 % (80 °C). Correspondingly, the half adsorption time (t1/2) is shortened by 29.5 % (60 °C) and 37.9 % (80 °C), which approximately saves 16.66 × 103 kJ (60 °C) and 31.31 × 103 kJ (80 °C) of energy. Through mathematical modelling, the factors that influenced the colour depth occured in the following order of importance: Concentration > pH > Temperature. Under optimal condition (GECLE concentration 9.36 g/L, pH 1.63 and temperature 61.70 °C), a theoretical maximum K/S value of 10.25 is achieved. Integrating the analyses above, a triple interactive scheme among TMC, GECLE and cotton fibre is proposed. GECLE (10 g/L) treated cotton deactivates up to 95% of Escherichia coli with 80% retention after 5 repeated launderings, and also provides an ‘Excellent’ rate of UV shielding performance. In general, the ultrasonic-assisted eco-dyeing and finishing process for cotton is explored in depth from practical and theoretical perspectives, which pushes forward the development of sustainable textile industry.