We present ALMA observations and multiwavelength spectral energy distribution ( SED ) analysis in a WISE -selected , hyperluminous dust-obscured quasar W0533 - 3401 at z = 2.9 . We derive its physical properties of each component , such as molecular gas , stars , dust and the central supermassive black hole ( SMBH ) . Both the dust continuum at 3 mm and the CO ( 3 - 2 ) line are detected . The derived molecular gas mass M _ { gas } = 8.4 \times 10 ^ { 10 } M _ { \odot } and its fraction f _ { gas } = 0.7 suggest that W0533 - 3401 is gas-rich . The star formation rate ( SFR ) has been estimated to be \sim 3000 - 7000 M _ { \odot } yr ^ { -1 } by using different methods . The high values of SFR and specific SFR suggest that W0533 - 3401 is a maximum-starburst . The corresponding gas depletion timescales are very short ( t _ { depl } \sim 12 - 28 Myr ) . The CO ( 3 - 2 ) emission line is marginally resolved and has a velocity gradient , which is possibly due to a rotating gas disk , gas outflow or merger . Finally , we infer the black hole mass growth rate of W0533 - 3401 ( { \dot { M } } _ { BH } = 49 M _ { \odot } yr ^ { -1 } ) , which suggests a rapid growth of the central SMBH . The observed black hole to stellar mass ratio M _ { BH } / M _ { \star } of W0533 - 3401 , which is dependent on the adopted Eddington ratio , is over one order of magnitude higher than the local value , and is evolving towards the evolutionary trend of unobscured quasars . Our results are consistent with the scenario that W0533 - 3401 , with both a gas-rich maximum-starburst and a rapid black hole growth , is experiencing a short transition phase towards an unobscured quasar .