Transition metal light elements compounds (TMLEs) are a kind of robust functional materials due to high hardness, high melting point, superior conductivity, magnetic properties, and superconductivity. And high hardness allows TMLEs can be used in extreme evironment. While, synthesizing TMLEs need high pressure and high temperature (HPHT) conditions to overcome the energy barrier. Although many TMLEs were synthesized by HPHT, the growth mechanism is still mysterious. Summary of TMLEs synthesized by HPHT is significant to understand the growth process and developing of new TMLEs. In this work, the TMLEs synthesized by HPHT which include our groups research experience and other relevant literatures are summarized. The TMLEs include transition metal borides (TMBs), transition metal carbides (TMCs), and transition metal nitrides (TMNs). The starting materials, experimental conditions, and morphologies etc. are analyzed. It can be found that proportion of starting materials and the suitable temperature are very important to obtain the single phase of TMBs; the boron subunit in TMBs is related to growth kinetics, which induces step growth process; choosing different starting materials of carbon and nitrogen will define the growth process of TMLEs. Synthesizing single crystal with millimeter size in the future is meaningful to understand the basic properties of TMLEs. And study the new structure of TMLEs which has high of light elements is still urgent. With developing of new materials, TMLEs will be a kind of irreplaceable robust materials in the future.