The young binary system HD 350731 is a noteworthy laboratory for studying early-type binaries with similar components .
We present here the analysis of differential multi-color photometric and spectroscopic observations for the double-lined detached system .
Accurate absolute parameters were determined from the simultaneous solution of light and radial velocity curves for the first time .
HD 350731 consists of two B8V-type components having masses and radii respectively of M _ { 1 } = 2.91 \pm 0.13 M _ { \odot } , M _ { 2 } = 2.80 \pm 0.14 M _ { \odot } , R _ { 1 } = 2.11 \pm 0.05 R _ { \odot } and R _ { 2 } = 2.07 \pm 0.05 R _ { \odot } .
The effective temperatures were determined based on analysis of disentangled spectra of the components and derived to be 12000 \pm 250 K and 11830 \pm 300 K for the primary and secondary components , respectively .
The measured projected rotational velocities , 69.2 \pm 1.5 km s ^ { -1 } for primary and 70.1 \pm 1.7 km s ^ { -1 } for secondary , were found closer to the pseudo-synchronous velocities of the components .
Comparison with evolutionary models suggests an age of 120 \pm 35 Myr .
Kinematic analysis of the unevolved binary system HD 350731 revealed that it belongs to the young thin-disc population of the Galaxy .