**2. Preliminaries**

In this section, we will explain how the MCDM method works, and we review some basic knowledge, including LTS, HFLTS, the score function of HFLTS, and the linguistic scale function. Some existing distance measures and similarity measures of HFLTSs are also introduced. In this paper, we denote *X* = {*<sup>x</sup>*1, *x*2, ··· , *xn*} as the discourse set.
