Due to its relatively low cost and remote detection characteristics, optical temperature sensing technology based on FIR has received widespread attention. At present, there is a lack of theoretical guidance on how to purposefully improve or guide the development of high-performance temperature sensing materials. Herein, the structure of a novel material K7MgSc2B15O30 has been confirmed by the XRD analysis. Furthermore, the effect of Zn on the crystal structure and the photoluminescence (PL) properties of K7MgSc2B15O30:Mn2+ has been studied. The PL spectra analysis of a series of Mn2+ doped K7MgSc2B15O30 luminescence materials indicates that two kinds of Mn2+ emitting centers (Mn(1) and Mn(2)) exist due to the two possible substitution sites Mg2+ and Sc3+. With the increasing of Zn2+, the intensity ratio of Mn(2) to Mn(1) improves from 1.01 to 1.88 at room temperature. Especially, the thermal stability of Mn(1) and Mn(2) gradually decrease with the increasing of Zn2+ contents, which can be due to the lengthening of Zn/Mg–O bonds and the lattice distortion of ScO6, respectively. Finally, their temperature sensing sensitivity has been enhanced by the doping of Zn2+, which has a close relation to the different effect of the thermal stability of Mn(1) and Mn(2). This work is expected to provide new ideas for the development of high-performance temperature sensing materials based on FIR, and is helpful to understand the relationship between the crystal structure and luminescence properties.