Abstract: To improve the accuracy and reliability of the calculation of concrete-formwork lateral pressure, a series of pressure test were carried out. The test data and the calculated value of different specifications were analyzed in the way of comparison. Then, a calculation model for concrete formwork lateral pressure was established based on Janssen theory and a calculation formula was derived. The reliability of the formula was proved by the experimental data. Research showed that there exist some potential safety problems as well as large dispersion in formwork lateral pressure calculated by the current codes. The model proposed can more accurately predict the lateral pressure with high reliability and lower dispersion when compared with the test value.