To seek appropriate technical methods for EOR in offshore deep extra-heavy oil reservoirs，a large-scale model of high temperature and high pressure sand packing was constructed according to the similarity theory and the geological characteristics of LD16-1 oilfield in the Bohai Sea. The physical simulation experiments of steam-assisted gravity drainage （SAGD）and multi-component thermal fluid-assisted gravity drainage（MAGD）were conducted in this sand packed model.Research results show that：MAGD has characters of high production capacity in early stages and fast decline in later production compared with SAGD. The ultimate recovery degree of reserves and cumulative oil-steam ratio has increased by 4.7% and 0.445 respectively. Amounts of injected non-condensate gas（CO2 and N2）may play the role of energy supplement，viscosity reduction，elastic energy increase and interfacial tension reduction. For MAGD technique，the injection temperature is the main controlling factor of the production performance. There is a reasonable gas water ratio since too much gas water ratio brings poorer recovery effect. Increasing injection rate and the proportions of CO2 in the non-condensate gas can improve the recovery effect. In addition，numerical simulation results have 93.19% fitting precision of the physical simulation results in a scaled numerical model.