The invention provides a valve device and physical property analysis equipment. The valve device comprises a valve body and a main needle valve rod, wherein the valve body is provided with a main valve cavity and one or more opening channels; the opening channels are communicated with the main valve cavity; an opening, communicated with the bottom of the valve body, of the main valve cavity is provided with a first seal matching part; the main needle valve rod is inserted in the main valve cavity; a second seal matching part is arranged at one end of the main needle valve rod; and the main needle valve rod is provided with a first position for sealing the first seal matching part and the second seal matching part to close the opening, and a second position for opening the first seal matching part and the second seal matching part to open the opening. As the position of the sealed opening is positioned at the bottom of the valve body, that is, the valve body is mounted on the equipment and then faces one end of the cavity, and materials cannot enter the valve cavity of the valve body, so that dead volume in the valve cavity is prevented and damage of the detecting result accuracy caused by excessive dead volume is also prevented.