In this study, cucumber peel (CP) was treated with Calcium Hydroxide i.e. Ca(OH)2 and its thermal behavior was examined. The pre‐treated cucumber peel (PTCP) was thermally degraded mainly through three steps; first, moisture and light volatile compounds loss (30–132°C); second, primary devolatilization (132 to 337°C) involving intense degradation with mainly re‐formation process and third and final, secondary reactions (337 to 800°C). Lower PTCP activation energy (192.77–183.33 KJ/mol) reflects its easy thermal conversion initiation. The non‐condensable compounds (CO2 & CH4) and condensable products (H2O, CH3CH2OH, CH3COOH, C=C, C6H5OH, HCOOH) were found as 29.75% and 70.25% respectively determined by TG‐FTIR analysis. While, with temperature, relative concentration of condensable compounds decrease significantly and found as 61.38% and 42.5% at lower and higher temperature respectively. By Py/GC–MS analysis, presence of the high energy optimizing compounds and valuable chemicals, i.e. toluene (5.12%), benzene (4.31%) and phenols (27.38%) was confirmed. All these datasets shows that pre‐treatment of CP with Ca(OH)2 might be suitable approach to produce Bioenergy and Bio‐chemicals.