Vehicle lamp control device and vehicle lamp system

A control device (100) of a vehicle lamp (10) includes: a receiving section (102) which receives an acceleration value usable to derive a tilt angle (Θ) of a vehicle to a horizontal plane, wherein the tilt angle of the vehicle to the horizontal plane is represented as a total angle (Θ); and a control section (104) which controls an optical axis adjustment of the vehicle lamp. The control section derives from the total angle a first and a second provisional vehicle posture angles (Θv1, Θv2) based on a first and a second calculation method, respectively, corrects the first or second provisional vehicle posture angle so that a difference between the first and the second provisional vehicle posture angles becomes small, sets the corrected provisional vehicle posture angle to the vehicle posture angle (Θv), and outputs a control signal for instructing the optical axis adjustment of the vehicle lamp according to the vehicle posture angle.