To continuously power the monitoring equipment on the transmission tower side， this paper studies the photovoltaic/thermoelectric（PV/T）coupling energy harvesting theory of high energy utilization efficiency that accounts for Tower-side spatial characteristics and field-source properties， and designs an optimized PV/T full-spectrum coupling architecture. Using a finite element simulation model， the paper validates the photothermal coupling theory and the optimization method under constraints such as heat transfer and efficient recovery and irradiance concentration. Experiments incorporating the hybrid energy-management circuit show that， compared with the conventional PV array， the proposed structure raises the average irradiance-to-electricity conversion efficiency by 3.39% （up to 25.33%）. The PV and thermo-electric modules are tightly and symmetrically coupled within the confined volume， delivering a peak output of 2.09 W. Additionally， the PV module’s temperature rise is reduced by 7.17 ℃ on average， extending its lifetime and improving its efficiency， while the thermoelectric module’s output matches theoretical expectations and satisfies the design requirements for hybrid operation. Finally， after dynamic matching with charge/discharge control， the solar and thermal energy of markedly different levels can be exploited rationally to meet the higher power and dynamic-response demands of the powered equipment.