At the end of the decade, the Roman microlensing survey is expected to detect 30000 microlensing events, that includes 1500 cold planets. In 2022, the Euclid space mission will be launched and will start its main survey just after reaching its stable orbit at L2. I will present the capabilities of two Euclid-Roman joint surveys. I will first highlight the potential of a small survey of the Roman microlensing fields during the first month of the Euclid mission. I will show how these observations are efficient to collect unique constraints on the relative proper motions and lens fluxes of the microlensing events that Roman will detect \(\sim\)5 years later. The second survey consist of simulatenous observation of the Roman and Euclid. Because Roman and Euclid will share similar orbit at L2, a joint-surveys allows the detection of the microlensing parallax for a large fraction of the microlensing events, including lenses of planetary mass. These constraints will be of first importance to reveal the distribution of low-mass lenses in the Milky Way.