Liang, H. Chen, M.W. Deng, X.B. Diao, Q.S. Gao, L. Hong, Z. Li, G. Li, M. Liu, Z.K. Lu, Y.S. Shen, D.S. Sheng, W.F. Wang, S.F. Yang, Y. Yue, Z.Y. Zhang, L. Zhang, S. Zhang, Y.S. Zhou, A.Y. JACoW Publishing Geneva, Switzerland HEPS is the first low emittance 4th generation light source in China, as monochromators are often limiting the performance of beamlines, many challenges are faced to preserve the quality of the beam. In order to meet the stringent and versatile requirements of 12 in house developed monochromators for different beamlines, several core technologies have been studied and developed. Stability considerations, vibration measurement system and methods are introduced, stability below 10 nrad RMS are measured for operation conditions by laser interferometers. Thermal resistance study at low temperature was carried out, enabling more accurate FEA of cooling. Clamping deformation of crystals at low temperature are experimentally studied, slope errors below 0.1 microradian RMS are measured. Design and test results on different types of monochromators will also be presented. Results show that the in house developed monochromators are able to meet the requirements of HEPS beamlines.