The utility model relates to a smooth measuring device and flexible integrated circuit device of laminating in advance, wherein, smooth measuring device includes: relative base and the test platform who sets up, be located the pressure sensing paper that test platform deviates from base one side, be located guide, sleeve between base and the test platform to and be located the locking mechanism between sleeve and the guide. But the voltage limiting unit among the above -mentioned smooth measuring device is in the dynamics within range of pressure sensing paper sensing in the time of can making the numerical value of the interact power between base and the test platform the biggest, but and then make test platform to the pressure value of pressure sensing paper at the dynamics within range of pressure sensing paper sensing when the biggest, consequently, utilize above -mentioned smooth measuring device, but can guarantee that the pressure that makes pressure sensing paper receive reaches and no longer than the dynamics scope of its sensing. Consequently, it is higher, to utilize this smooth measuring device to carry out the degree of accuracy of flatness test.