Abstract: The continuous development of offshore engineering construction has put forward higher requirements for offshore geotechnical engineering investigation. Due to the fact that conventional marine in-situ test is difficult to meet the economic, fast and convenient requirements of projects such as offshore wind power development, port dredging and pipeline and cable surveys, free fall penetration test has attracted attention. The development of free fall penetration test is reviewed and a kind of free fall penetration technology is introduced for marine soft soil. The methods of undrained shear strength of soft soil and classification of sediment based on FFP are summarized. The authors designed a new free fall piezocone penetrometer for evaluating the characteristics of offshore geotechnical engineering and proposed the FFP engineering characteristic evaluation framework. The analysis shows that free fall penetration test has a broad application prospect in offshore geotechnical engineering testing.