Investigation of high temperature superconductivity has achieved tremendous progress since the discovery of cuprate superconductors in 1986. Besides the determination of the phase diagram and pairing symmetry of high-Tc superconductors, a large number of novel physical phenomena, including the pseudogap effect, charge-spin separation, linear resistivity and strong superconducting phase fluctuation, have been discovered and enriched the picture of microscopic quantum world. However, the mechanism of high-temperature superconductivity remains a mystery. It is also difficult to understand a number of anomalous quantum phenomena observed in cuprate superconductors within the existing framework of quantum many-body theory. To solve these problems, new measurement technology with new quantum many-body theory and computational method should be developed. In particular, it is desired to develop an experimental method that can be used to reveal unambiguously the mechanism of superconducting pairing by directly tuning and probing the interactions between electrons and phonons or other elementary quasiparticle excitations.