The invention relates to the substation equipment contact temperature monitoring technology, in particular to a substation equipment contact state on-line monitoring star network platform. The problems that an existing substation equipment contact temperature monitoring platform is instable in transmission, poor in transmission reliability, poor in antijamming capability, high in wiring difficulty, poor in measurement accuracy and measurement safety, high in maintenance cost and low in measurement precision are solved. The substation equipment contact state on-line monitoring star network platform comprises two collection layers, a transmission layer and a monitoring layer. Each collection layer comprises m SAW temperature sensors, m normal small spiral antennas, a spiral arm dipole antenna and a wireless temperature collector, wherein the m SAW temperature sensors are connected with the m normal small spiral antennas in a one-to-one corresponding mode, and the m normal small spiral antennas and the spiral arm dipole antenna form a star topological structure together. The substation equipment contact state on-line monitoring star network platform is applicable to substations.