Multiplexed molecular profiling of tissue microenvironments, or spatial omics, can provide critical insights into cellular functions and disease pathology. In this talk, I will give a brief introduction to our recently developed deep spatial proteomics platform, which aims to visualize the global proteome (>3000 proteins) at subcellular resolution on thin tissue sections. In distinction to existing spatial proteomics tools that use affinity probes to recognize proteins, our platform employs liquid chromatography-mass spectrometry (LC-MS) to directly identify all proteins present in the tissue. We developed an excimer laser (193 nm)-based ablation system to achieve flexible and highly precise sample isolation. To improve sample preparation efficiency, we developed a microfluidic droplet-based processing system, named nanoPOTS (nanodroplet processing in one pot for trace samples). We demonstrated nanoPOTS can efficiently process single cells or laser-isolated tissue samples for proteomic analysis. A couple of sample multiplexing method was also developed to improve the analysis throughput. Finally, I will present several biomedical applications using the deep spatial proteomics platform and provide our perspective on the future direction of deep spatial proteomics for tissue profiling.