The article summarizes the development and latest research progress of solid-state crystal growth(SSCG) technology. First of all, the phenomenon of abnormal grain growth in ceramic sintering and metallurgy process is reviewed, and the SSCG technology is also introduced. The process and application fields of the SSCG technology are introduced briefly. Some of typical application cases and development history of the SSCG technology are also described. Then, a new solid-state crystal growth technology: seed-free, solid-state crystal growth(SFSSCG) technology is introduced. The application of the SFSSCG technology in the lead-free ferroelectric and piezoelectric crystal, that is potassium sodium niobate based crystal, is introduced in detail, and the characteristics of this method are compared with the conventional high-temperature melt and SSCG method. Finally, based on the current discussion on the crystal growth mechanism of the solid-state method, a new comprehensive crystal growth mechanism is proposed for the SFSSCG method. And the current problems and future development of the SFSSCG technology are briefly described and prospected, respectively.