A programmable bandwidth-tunable and wavelength-variable fiber grating filter based on a linearly chirped fiber Bragg grating (LCFBG) and thermal-optical phase shift technique is proposed. The number of transmission peaks, filter bandwidth, central wavelength and wavelength spacing can be adjusted independently. Due to the thermo-optical effect, a phase shift can be induced along the LCFBG by heating a small portion of the LCFBG, then a transmission peak can be obtained within the stop band. The specific location of fiber grating is accurately heated by using a thermal printer head as a digital heating unit. The number of the transmission peaks and the wavelength spacing can be set by changing the number and the spacing of the heating points, respectively. And the peak′s bandwidth can be tuned by changing the width of the heating region. Tunable bandwidth of transmission peak between 0.07 nm and 1.55 nm, central wavelength of transmission peak ranging from 1547.16 nm to 1558.64 nm and the minimum wavelength spacing of 0.95 nm can be achieved using this filter.