  Blazars are variable targets in the sky, whose variation mechanism remains an
open question. In this work, we make a comprehensive study on the variation
phenomena of the spectral index and polarization degree (PD) to deeply
understand the variation mechanism of B2 1633+382 (4C 38.41). We use the local
cross-correlation function (LCCF) to perform the correlation analysis between
multi-wavelength light curves. We find that both $\gamma$-ray and optical
$V$-band are correlated with the radio 15 GHz at the beyond 3$\sigma$
confidence level. Based on the lag analysis, the emitting regions of
$\gamma$-ray and optical locate at $14.2_{-2.4}^{+0}$ pc and
$14.2_{-8.3}^{+8.3}$ pc upstream of the core region of radio 15 GHz, and are
far away from the broad-line region (BLR). The broad lines in the spectrum
indicate the existence of the accretion disk component in the radiation. Thus,
we consider the two-component (TC) model, which includes the relative constant
background component and the varying jet component to study the variation
behaviors. The Markov Chain Monte Carlo (MCMC) procedure is adopted to study
the physical parameters of the jet and the background components. To some
extent, the study of normalized residuals indicates that the TC model fits
better than the linear fitting model. The jet with helical magnetic field is
hopeful to explain the variation, and the shock in jet model is not completely
ruled out.
