The Large Hadron Collider (LHC) upgrade, called High Luminosity LHC (HL-LHC) is planned for the next decade. A set of twin aperture beam orbit correctors positioned on the approaches to the ATLAS & CMS experiments will be development. The orbit corrector based on Canted Cosine Theta (CCT) design to achieve 5 Tm field integral and multipoles lower than 10 units in the twin aperture. Tow institutes (IHEP, IMP) and one company (WST) in China will work on the magnet R&D and series production. IMP in charge of the performance test at 4.2 K including field strength and field quality. This paper presents the results of the magnetic field measurements of the first series magnet by a rotating coil probe.