Abstract: Quantum emitters serve as the building blocks of quantum network, connecting quantum computing, quantum communication and quantum metrology. Semiconductor quantum dots (QDs) are widely considered as the best candidate for quantum emitters. By a decade of effort, the controllability, purity, brightness, indistinguishability, and coherence of QD emitters are greatly improved so that they are much closer to the application level. In this paper, the scientific and technological development of quantum emitters based on QDs were reviewed. Firstly, QD-based single photon sources have achieved indistinguishability of near unity, high purity, and high extraction efficiency. Secondly, QD-based entangled photon emitters have achieved high bit rate, high entanglement fidelity by improvements such as eliminating fine structure splitting. Thirdly, remarkable development has been made towards on-chip integration of QD emitters into planar circuits and nano-photonic systems. It turns out that quantum emitters based on semiconductor QDs are greatly potential to be applied in quantum information processing systems in the near future.