The invention discloses a production method of ultrafine titanium powder or titanium alloy powder. The method includes the steps: melting titanium or titanium alloy material into titanium melt or titanium alloy melt; subjecting the titanium melt or titanium alloy melt to primary centrifugal atomization; after primary centrifugal atomization, subjecting the titanium melt or titanium alloy melt to secondary centrifugal atomization; collecting titanium powder or titanium alloy powder obtained by the primary and secondary centrifugal atomization and cooling so as to obtain ultrafine titanium powder or titanium alloy powder. The steps are performed in the atmosphere of an insert gas. The ultrafine titanium powder or titanium alloy powder is produced by the production method. An ultrafine metal powder production device is used for implementing the production method. The production method is high in production efficiency and low in energy consumption; the titanium powder or titanium alloy powder produced by the production method is spheres or similar spheres and is low in oxygen content, high in density, fine in mobility and low in fineness.