  Multi-band photometric observations of eleven totally eclipsing contact
binaries were carried out. Applying the Wilson-Devinney program, photometric
solutions were obtained. There are two W-subtype systems, which are CRTS
J133031.1+161202 and CRTS J154254.0+324652, and the rest systems are A-subtype
systems. CRTS J154254.0+324652 has the highest fill-out factor with 94.3$\%$,
and the lowest object is CRTS J155009.2+493639 with only 18.9$\%$. The mass
ratios of the eleven systems are all less than 0.1, which means that they are
extremely low mass ratio binary systems. We performed period variation
investigation and found that the orbital periods of three systems decrease
slowly, which may be caused by the angular momentum loss, and of six systems
increase slowly, which indicates that the materials may transfer from the
secondary component to the primary component. LAMOST low$-$resolution spectra
of four objects were analyzed, and using the spectral subtraction technique,
H$\alpha$ emission line was detected, which means that the four objects exhibit
chromospheric activity. In order to understand their evolutionary status, the
mass-luminosity and mass-radius diagrams were plotted. The two diagrams
indicate that the primary component is in the main sequence evolution stage,
and the secondary component is above TAMS, indicating that they are
over-luminous. To determine whether the eleven systems are in stable state, the
ratio of spin angular momentum to orbital angular momentum ($J_{s}/J_{o}$) and
the instability parameters were calculated, and we argued that CRTS
J234634.7+222824 is on the verge of a merger.
