1 Introduction

2 Effect of high pressure on the electronic and crystal structure of condensed matter

2.1 Effect of high pressure on the outer electronic structure of the elements

2.2 An increase in the atomic number caused by high pressure

2.3 Abnormal oxidation states of elements caused by high pressure

2.4 Structural phase transitions caused by high pressure

2.5 Effect of high pressure on band structure

2.6 Effect of high pressure on crystal defects

2.7 State changes caused by high pressure

3 Chemical reaction of condensed matter under high pressure

3.1 Metallization of hydrogen

3.2 High-pressure polymerization of small inorganic molecules

3.3 High-pressure polymerization of organic compounds

3.4 High-pressure synthesis of poly-nitrogen compounds

3.5 High-pressure synthesis of MOFs

3.6 High-pressure synthesis of inert element oxides

3.7 Reaction of alkali metal with inert gas under high pressure

3.8 Effect of high pressure on the morphology and structure of nanocrystals

3.9 Synthesis of Na-Cl compounds under high pressure

3.10 Promoting effect of high pressure on chemical reaction

4 Conclusions and outlook